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director of the observatory at flagstaff, arizona; non-resident professor 
of astronomy at the massachusetts institute of technology; fellow of 
the american academy of arts and sciences; membre de la socie'te 
astkonomique de france; member of the astronomical and astro- 
physical society of america; mitglied der astronomische ge- 
ski.i.schaft; membre de la socikte belge d'astronomie; 
honorary member of the sociedad astronomica de mex- 
ico; janssen medalist of the societe a8tronomique de 
france, 1904, for researches on mars; etc., etc. 


Neto gorfc 



All rights reserved 

COPYRIOHT, 1 ( .K)6, 


Set up and etectrotyped. Published December, 1906. 


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Bmltfa CO. 

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Eleven years have elapsed since the writer's first 
work on Mars was published in which were recorded 
the facts gleaned in his research up to that time 
and in which was set forth a theory of their explana- 
tion. Continued work in the interval has confirmed 
the conclusions there stated ; sometimes in quite 
unexpected ways. Five times during that period 
Mars has approached the earth within suitable scan- 
ning distance and been subjected to careful and 
prolonged scrutiny. Familiarity with the subject, 
improved telescopic means, and long-continued train- 
ing have all combined to increased efficiency in the 
procuring of data and to results which have been 
proportionate. A mass of new material has thus 
been collected, some of it along old lines, some of 
it in lines that are themselves new, and both have 
led to the same outcome. In addition to thus push- 
ing inquiry into advanced portions of the subject, 
study has been spent in investigation of the reality 
of the phenomena upon which so much is based, and 
in testing every theory which has been suggested to 


account for them. From diplopia to optical inter- 
ference, each of these has been examined and found 
incompatible with the observations. The phenomena 
are all they have been stated to be, and more. Each 
step forward in observation has confirmed the genu- 
ineness of those that went before. 

To set forth science in a popular, that is, in a 
generally understandable, form is as obligatory as to 
present it in a more technical manner. If men are 
to benefit by it, it must be expressed to their com- 
prehension. To do this should be feasible for him 
who is master of his subject and is both the best 
test of, and the best training to, that post. Espe- 
cially vital is it that the exposition should be done 
at first hand ; for to describe what a man has him- 
self discovered comes as near as possible to making 
a reader the co-discoverer of it. Not only are thus 
escaped the mistaken glosses of second-hand knowl- 
edge, but an aroma of actuality, which cannot be 
filtered through another mind without sensible evap- 
oration, clings to t he account of the pioneer. Nor 
is it so hard to make any well-grasped matter com- 
prehensible to a man of good general intelligence as 
is commonly supposed. The whole object of science 
is to synthesize, and so simplify; and did we but 
know the uttermost of a subject we could make it 
singularly clear. Meanwhile technical phraseology, 


useful as shorthand to the cult, becomes meaningless 
jargon to the uninitiate and is paraded most by the 
least profound. But worse still for their employ 
symbols tend to fictitious understanding. Formulae 
are the anaesthetics of thought, not its stimulants; 
and to make any one think is far better worth while 
than cramming him with ill-considered, and therefore 
indigestible, learning. 

Even to the technical student, a popular book, if 
well done, may yield most valuable results. For noth- 
ing in any branch of science is so little known as its 
articulation, how the skeleton of it is put together, 
and what may be the mode of attachment of its 



Preface vii 



I. On Exploration 3 

II. A Departure-point 12 

III. A Bird's-eye View of Past Martian Discovery 20 

IV. The Polar Caps 32" 

V. "Behavior of the Polar Caps .... 41- 

VI. * Martian Polar Expeditions 54 

VII. White Spots 73 - 

VIII. Climate and Weather 82~ 

IX. Mountains and Cloud 96- 

X. The Blue-green Areas 108- 

XI. Vegetation 119 

XII. Terraqueousness and Terrestriality . . 128^ 

XIII. The Reddish-ochre Tracts 148-~ 

XIV. Summary 159 




1 The Canals 

. 173 


v Their System 

. 184 


Gemination of the Canals 

. 192 

I. The Diplopic Theory . 

. 196 

II. The Intkrference Theory . 

. 201 

III. The Illusion Theory . 

. 202 








liii Double C \nals 

XIX. Canals in the Dark Regions 

XX. Oases 

XXI. Carets <>n the Borders of the Great Dia- 


XXII. The Canals Photographed 271 


XXIII. Canals: Kinematic 281 

XXIV. 'Canal Development Individually Instanced . :i<>4 


XXVI. Ar< iic Canals and Polar Rifts . . . 82$ 

XXVII. Oases: Kinematic 888 


XXVIII. Constitution <>f the Canals and Oases . . :>:57" 

XXIX. Life -I s - 

XXX. Evidi n. i . . 888 

XXXI. Tin Husbanding or Water 366 


INDEX 888 



Mars' Hill 












The Hermitage . 

The San Francisco Peaks 

Martian Maps by: 

I. Beer and Maedler. 1840 
Kaiser. 1864 . 
Flammarion (Resume). 1876 
Green. 1877 . 
schiaparelli. 1877 
schiaparelli. 1879 
schiaparelli. 1881 


Lowell. 1894 . 

South Polar Cap. 
North Polar Cap. 

Lowell. 1896 . 

Lowell. 1901 . 

Lowell. 1905 . 
1905 . 
1905 . 

Mare Erythraeum, Martian date, December 30 
Mare Erythraeum, Martian date, January 16 
Mare Erythraeum, Martian date, February 1 
Mare Erythraeum, Martian date, February 21 
Mars, on Mercator's Projection .... 






















South Polar Cap in winter . . 
Hellas in winter 




White south >e Nectar and Solis Lacus 
northern cap hooded with vapor 

Nor mi rn Cap unm isri d 

I i r. >-l l ION OF PROST .... 

First northern bnow 
White in Elysium .... 
White in the Pons Hectoris 
Projection <>n terminator 

Links IN DARE AREA .... 

Map oi North America at the close of Archaean time 
North America at opening of Upper Silurian period 
Map of North America after the Appalachian revo- 

North America in the Cretaceous period 

North America, showing the parts under water in 

the Tertiary era .... 

L\i:iii'- 1>i.-i-t:t Areas. Western Hemisphere 
Earth's Desert Areas, Eastern Hemisphere 
Showing the Eumenides-Orcus 

Maui i \\ DOUBLES 

M IRTIAN DOl nil 9 

Mi. i in- .i Euphrates and Phison. June, 1003 


Tin Sabaeus Sinus, embouchure fob the double Hid- 


The Propontis, 1906 

Pons [mmor i ilis, June 19 ... . 
Utopi \ Regio. 1908 


Peculiar association oi rm Luoi [smenu with double 


Lucus [smi NIUS. M \i:< II. 1908 
Show ing si isonai i h inge. I 



Showing seasonal change. II ..... 285 

Mean Canal Cartouches . . . . . . . 298 

Showing development of the Brontes : 

I. February 25 306 

II. March 30 307 

III. April 3 307 

IV. May 4 308 

V. May 7 308 

VI. July 18 309 

Cartouches of the Brontes ....... 311 

Amenthes alone in February 319 

Amenthes feebler and still alone in March . . . 319 
Appearance of Thoth with Triton and curved Nepen- 
thes. Amenthes vanished, April 20 ... 320 
Advent of the Lucus Moeris. May 29 ... . 321 
Amenthes with Thoth-Nepenthes. July .... 322 
Cartouches of Amenthes, Thoth, and their combina- 
tion 323 

Phenology Curves Earth 342 

Phenology Curves Mars 343 






TpROM time immemorial travel and discovery 
-* have called with strange insistence to him who, 
wondering on the world, felt adventure in his veins. 
The leaving familiar sights and faces to push forth into 
the unknown has with magnetic force drawn the bold 
to great endeavor and fired the thought of those who 
stayed at home. Spur to enterprise since man first 
was, this spirit has urged him over the habitable globe. 
Linked in part to mere matter of support it led the 
more daring of the Aryans to quit the shade of their 
beech trees, reposeful as that umbrage may have been, 
and wander into Central Asia, so to perplex philolo- 
gists into believing them to have originated there; 
it lured Columbus across the waste of waters and 
caused his son to have carved upon his tomb that 
ringing couplet of which the simple grandeur still 
stirs the blood : 

A Castilla y a Leon 


(To Castile and Leon beyond the wave 
Another world Columbus gave ;) 


it drove the early voyagers into the heart of the vast 
wilderness, there to endure all hardship so that they 
might come where their kind had never stood before; 
and now it points man to the pole. 

Something of the selfsame spirit finds a farther 
field today outside the confines of our traversable 
earth. Science which has caused the world to shrink 
and dwindle has been no less busy bringing near what 
in the past seemed inaccessibly remote. Beyond our 
earth man's penetration has found it possible to pierce, 
and in its widening circle of research has latterly been 
made aware of another world of strange enticement 
across the depths of space. Planetary distances, not 
mundane ones, are here concerned, and the globe to be 
explored, though akin to, is yet very different from, 
our own. This other world is the planet Mars. 
Sundered from us by the ocean of ether, a fellow- 
member of our own community of matter there makes 
its circuit of the sun upon whose face features show 
which stamp it as cognate to that on which we live. 
In spite of the millions of miles of intervening mat- 
ter! rss void, upon it markings can be made out that 
distantly resemble our earth's topography and grow 
increasingly suggestive as vision shapes them better; 
and yet among the seemingly familiar reveal aspects 
which are completely strange. But more than this: 
over the face of it sweep changes that show it to be 


not a dead but a living world, like ours in this, and 
luring curiosity by details unknown here to further 
exploration of its unfamiliar ground. 

To observe Mars is to embark upon this enterprise; 
not in body but in mind. Though parted by a gulf 
more impassable than any sea, the telescope lets us 
traverse what otherwise had been barred and lands us 
at last above the shores we went forth to seek. Real 
the journey is, though incorporeal in kind. Since the 
seeing strange sights is the essence of all far wander- 
ings, it is as truly travel so the eye arrive as if the body 
kept it company. Indeed, sight is our only far viatic 
sense. Touch and taste both hang on contact, smell 
stands indebted to the near and even hearing waits on 
ponderable matter where sound soon dissipates away; 
only sight soars untrammeled of the grosser adjunct of 
the flesh to penetrate what were otherwise unfathom- 
able space. 

What the voyager thus finds himself envisaging 
shares by that very fact in the expansion of the sense 
that brought him there. No longer tied by means of 
transport to seas his sails may compass or lands his 
feet may tread, the traveler reaches a goal removed in 
kind from his own habitat. He proves to have ad- 
ventured, not into unknown parts of a known world, 
but into one new to him in its entirety. In extent 
alone he surveys what dwarfs the explorer's conquests 


on Earth. But size is the least of the surprises there 
in store for him. What confronts his gaze finds com- 
monly no counterpart on Earth. His previous knowl- 
edge stands him in scant stead. For he faces what is 
bo removed from every day experience that analogy no 
longer offers itself with safety as a guide. He must 
build up new conceptions from fresh data and slowly 
proceed to deduce the meaning they may contain. 
Science alone can help him to interpretation of what 
he finds, and above all must he wean himself from 
human prejudice and earthbound limitation. For he 
deals here with ultramundane things. With just 
enough of cosmogony in common to make decipher- 
ment not despairable this world is yet so different 
from the one he personally knows as to whet curiosity 
at every turn, lie is permitted to perceive what 
piques inquiry and by patient adding of point to point 
promises at last a rational result. 

Like mundane exploration, it is arduous too; ad 
astra per aspera is here literally true. For it is a 
journey nol devoid of hardship and discomfort by the 
way. Its starting-point preludes as much. To get 
conditions proper for his work the explorer must forego 
the haunts of men and even those terrestrial spots found 
by them most habitable. Astronomy now demands 
bodily abstraction of its devotee. Its deities are gods 
thai veil themselves amid man-crowded marts and 


impose withdrawal and seclusion for the prosecution of 
their cult as much as any worshiped for other reason 
in more primeval times. To see into the beyond re- 
quires purity; in the medium now as formerly in the 
man. As little air as may be and that only of the 
best is obligatory to his enterprise; and the securing it 
makes him perforce a hermit from his kind. He must 
abandon cities and forego plains. Only in places raised 
above and aloof from men can he profitably pursue 
his search, places where nature never meant him to 
dwell and admonishes him of the fact by sundry 
hints of a more or less distressing character. To 
stand a mile and a half nearer the stars is not to 
stand immune. 

Thus it comes about that today besides its temples 
erected in cities, monasteries in the wilds are being 
dedicated to astronomy as in the past to faith ; mon- 
asteries made to commune with its spirit, as temples 
are to communicate the letter of its law. Pioneers in 
such profession, those already in existence are but the 
precursors of many yet to come as science shall more 
and more recognize their need. Advance in knowl- 
edge demands what they alone can give. Primitive, 
too, they must be as befits the still austere sincerity 
of a cult, in which the simplest structures are found 
to be the best. 

Still the very wildness of the life their devotee is 


forced to lead has in it a certain fittingness for his post 
in its primeval detachment from the too earthbound, 
in concept as in circumstance. Withdrawn from con- 
tact with his kind, he is by that much raised above 
human prejudice and limitation. To sally forth into 
the untrod wilderness in the cold and dark of a 
winter's small hours of the morning, with the snow feet 
deep upon the ground and the frosty stars for mute 
companionship, is almost to forget one's self a man 
for the solemn awe of one's surroundings. Fitting 
portal to communion with another world, it is through 
such avenue one enters on his quest where the com- 
mon and familiar no longer jostle the unknown and 
the strange. Nor is the stillness of the stars invaded 
when some long unearthly howl, like the wail of a lost 
soul, breaks the slumber of the mesa forest, marking 
the prowling presence of a stray coyote. Gone as it 
came, it dies in the distance on the air that gave it 
birth; and the gloom of the pines swallows up one's 
vain peering after something palpable, their tops alone 
decipherable in dark silhouette against the sky. From 
amid surroundings that for their height and their 
intenancy fringe the absolute silence of space the 
observer must set forth who purposes to cross it to 
another planetary world. 

Bui the isolation of his journey is not always so for> 
bidding. His coming back is no less girt with grandeur 



of a different though equally detached a kind. Even 
before the stars begin to dim in warning to him to re- 
turn, a faint suffusion as of half-suspected light creeps 
into the border of the eastern sky. Against it, along 
the far pine-clad horizon, mesa after mesa in shaggy 
lines of sentineling earth, stands forth dark marshaled 
in the gloom, informed with prescience of what is soon 
to come. Imperceptibly the pallor grows, blanching 
the face of night and one by one extinguishing the stars. 
Slowly then it takes on color, tingeing ever so faintly 
to a flush that swells and deepens as the minutes pass. 
One had said the sky lay dreaming of the sun in pale 
imagery at first that gathers force and feeling till the 
dreamer turns thus rosy red in slumbering supposition 
of reality. Then the blush dies out. The crimson fades 
to pink, the pink to ashes. The stars have disappeared 
and yet it is not day. It is the supreme moment of the 
dawn, the hush with which the Earth awaits its full 
awakening. For now again the color gathers in the east, 
not with the impalpable suffusion it had before but 
nearer and more vivid. No longer reflectively remote, 
rays imminent of the sun strike the upper air, the most 
adventurously refrangible turning the underside of a 
few stray clouds into flame-hued bars of glowing metal. 
They burn thus in the silent east first red, then orange, 
and then gold, each spectral tint in prismatic reve- 
lation coming to join the next till in a sudden 

10 WARS AM) ITS CANALS chap., 

blinding hurst of splendor the solar disk tops the 
horizon's rim. 

Not less impressive is the journey when the afternoon 
watch has replaced the morning vigil by the drawing of 
the planet nearer to the sun. Lost in the brilliance of 
the dazzling sky, the planet lies hid from the senses' 
search. The quest were hopeless did not the mind guide 
the telescope to its goal. To theory alone is it visible 
still, and so to its predicted place the observer sets his 
circles, and punctual to the prophecy the planet swings 
into the field of view. One must be dulled by long 
routine to such mastery of mind not to have the act 
itself clothe with a sense of charmed withdrawal the 
object of his quest. 

So much and more there are of traveler's glimpses 
by the way, compensation that offsets the frequent dis- 
comfort, and even balking of his purpose by inoppor- 
tune cloud. For the best of places is not perfect, and a 
storm will sometimes rob him of a region he wished to 
Bee. I le must learn to wait upon his opportunities and 
then no less to wait for mankind's acceptance of his 
results; for in common with most explorers he will 
encounter on his return that final penalty of penetra- 
tion, the certainty at first of being disbelieved. 

In such respect he will be even worse off than were the 
other world discoverers of the fifteenth and sixteenth 
centuries. For they at least could offer material proof 

chap, i ON EXPLORATION 11 

of things that they had seen. Dumb Indians and gold 
spoke more convincingly than the lips of the great navi- 
gators. To astronomy, too, that other world was due. 
Without a knowledge of the earth's shape and size got 
from Francisco of Pisa, Columbus had never adventured 
himself upon the deep. But more than this, an as- 
tronomer it was, in the person of Americus Vespucius, 
who first discovered the new world, by recognizing it 
as such ; Columbus never dreaming he had lighted upon 
a world that was new. Nor does it impair one jot or 
tittle of his glory that he knew it not. Nothing can 
deprive him of the imperishable fame of launching 
forth into the void in hope of a beyond, though he 
found not what he sought but something stranger still. 
So, curiously, has it been with the trans-etherian. 
To Schiaparelli the republic of science owes a new and 
vast domain. His genius first detected those strange 
new markings on the Martian disk which have proved 
the portal to all that has since been seen, and his courage 
in the face of universal condemnation led to explora- 
tion of them. He made there voyage after voyage, 
much as Columbus did on Earth, with even less of rec- 
ognition from home. As with Columbus, too, the full 
import of his great discovery lay hid even to him and 
only by discoveries since is gradually resulting in rec- 
ognition of another sentient world. 



A S the character of the travel is distinctive, so the 
-*--*- outcome of the voyage is unique. If he choose his 
departure-point aright, the observer will be vouchsafed 
an experience without parallel on Earth. To select 
this setting-out station is the first step in the journey 
upon which everything depends. For it is essential 
to visual arrival that a departure-point be taken where 
definition is at its best. Now, so far as our present 
knowledge goes, the conditions most conducive to 
good seeing turn out to lie in one or other of the two 
great desert belts that girdle the globe. Many of us 
are unaware of the existence of such belts and yet they 
are among the most striking features of physical geog- 
raphy. Could we get off our globe and view it from 
without we should mark two sash-like bands of coun- 
try, to the poleward side of cither tropic, where the sur- 
face itself lay patently exposed. Unclothed of verdure 
themselves they would stand forth doubly clear by con- 
trast. For elsewhere cloud would hide to a greater or 
less extent the actual configuration of the Earth's 
topography to an observer scanning it from space. 


chaf. ii A DEPARTURE-POINT 13 

One of these sash-like belts of desert runs through 
southern California, Arizona, New Mexico, the Sahara, 
Arabia Petrsea and the Desert of Gobi; the other 
traverses Peru, the South African veldt, and Western 
Australia. They are desert because in them rain is 
rare; and even clouds seldom form. In a twofold 
way they conduce to astronomic ends. Absence of 
rain makes primarily for clear skies and secondarily 
for steady air; and the one of these conditions is no 
less vital to sight than the other. Water vapor is a 
great upsetter of atmospheric equilibrium and com- 
motion in the air the spoiler of definition. Thus from 
the cloudlessness of their skies man finds in them most 
chance of uninterrupted communion with the stars, 
while by suitably choosing his spot he here obtains as 
well that prime desideratum for planetary work, as 
near a heavenly equanimity in the air currents over 
his head as is practically possible. 

From the fact that these regions are desert they are 
less frequented of man, and the observer is thus perforce 
isolated by the nature of the case, the regions best 
adapted to mankind being the least suited to astronomic 
observations. In addition to what nature has thus 
done in the matter, humanity has further differentiated 
the two classes of sights by processes of its own contriv- 
ing. Not only is civilized man actively engaged in de- 
facing such part of the Earth's surface as he comes in 

14 MAES AM) ITS CANALS chap, n 

contact with, he is equally busy blotting out his sky. 
In the latter uncommendable pursuit he has in the last 
quarter of a century made surprising progress. With a 
success only too undesirable his habitat has gradually 
become canopied by a welkin of his own fashioning, 
which has rendered it largely unfit for the more delicate 
kinds of astronomic work. Smoke from multiplying 
factories by rising into the air and forming the nucleus 
about which cloud collects has joined with electric 
lighting to help put out the stars. These concomitants 
of advancing civilization have succeeded above the 
dreams of the most earth-centred in shutting off sight 
of the beyond so that today few city-bred children 
have any conception of the glories of the heavens 
which made of the Chaldean shepherds astronomers in 
spite of themselves. 

The old world and the new are alike affected by 
such obliteration. Long ago London took the lead 
with fogs proverbial wholly due to smoke, fine parti- 
cles of solid matter in suspension making these points 
of condensation about which water vapor gathers to 
form cloud. With the increase of smoke-emitting 
chimneys over the world other centres of population 
have followed suit till today Europe and eastern North 
America vie with each other as to which sky shall be 
the most obliterate. Even when the obscuration is not 
patent to the layman it is evident to the meteorologist 

chap, ii A DEPARTURE-POINT 15 

or astronomer. By a certain dimming of the blue, 
smoke or dust reveals its presence high up aloft as 
telltalely as if the thing itself were visible. Some time 
since the writer had occasion to traverse Germany in 
summer from Gottingen to Cologne and in so doing was 
impressed by a cloudiness of the sky he felt sure had not 
existed when he knew it as a boy. For the change 
was too startling and extensive to be wholly laid to the 
score of the brighter remembrances of youth. On 
reaching Cologne he mentioned his suspicion to Klein, 
only to find his own inference corroborated; observa- 
tions made twenty years ago being impracticable today. 
Two years later in Milan Celoria told the same story, 
the study of Mars having ceased to be possible there foi' 
like cause. Factory smoke and electric lights had com- 
bined to veil the planet at about the time Schiaparelli 
gave up his observations because of failing sight. With 
a certain poetic fitness the sky had itself been blotted 
just at the time the master's eye had dimmed. 

America is not behind in this race for sky extinction. 
In the neighborhood of its great cities and spreading into 
the country round about the heavens have ceased to be 
favorable to research. Not till we pass beyond the 
Missouri do the stars shine out as they shone before the 
white man came. 

Few astronomers even fully appreciate how much this 
means, so used does man get to slowly changing condi- 


tions. It amounts, indeed, between Washington and 
Arizona to a whole magnitude in the stars which may 
be seen. At the Naval Observatory of the former 
sixty-four stars were mapped in a region where with a 
slightly smaller glass one hundred and seventy-two were 
charted at Flagstaff. 

Besides their immediate use as observing stations 
these desert belts possess mediate interest on their own 
account in a branch of the very study their cloudless- 
ness helps to promote, the branch here considered, the 
study of the planet Mars. They help explain what they 
permit to be visible. For in the physical history of the 
Earth's development they are among the latest phe- 
nomena and mark the beginning of that stage of world 
evolution into which Mars is already well advanced. 
They are symptomatic of the passing of a terraqueous 
globe into a purely terrestrial one. Desertism, the state 
into which every planetary body must eventually come 
and for which, therefore, it becomes necessary to coin a 
word, has there made its first appearance upon the 
Earth. Standing as it does for the approach of age 
in planetary existence, it may be likened to the first 
gray hairs in man. Or better still' it corresponds to 
early autumnal frost in the passage of the seasons. 
For the beginning to age in a planet means not decrep- 
itude in its inhabitants but the very maturing of this 
it- fruit. Evolution of mind in its denizens continues 

chap, ii A DEPARTURE-POINT 17 

long after desolation in their habitat has set in. 
Indeed, advance in brain-power seriously develops 
only when material conditions cease to be bodily pro- 
pitious and the loss of corporeal facilities renders its 
acquisition necessary to life. 

The resemblance, distant but distinctive, of the cli- 
matic conditions necessary on earth for the best scan- 
ning of Mars with those which prove to be actually exist- 
ent on that other world has a bearing on the subject 
worth considerable attention. It helps directly to an 
understanding and interpretation of the Martian state 
of things. Though partial only, the features and traits 
of our arid zones are sufficiently like what prevails on 
Mars to make them in some sort exponent of physical 
conditions and action there. Much that is hard of 
appreciation in a low, humid land shows itself an every- 
day possibility in a high and dry one. The terrible 
necessity of water to all forms of life, animal or vegetal, 
so that in the simple thought of the aborigines rain is 
the only god worth great propitiation upon the due 
observance of which everything depends, brings to one 
a deeper realization of what is really vital and what but 
accessory at best. One begins to conceive what must 
be the controlling principle of a world where water is 
only with difficulty to be had, and rain unknown. 

But in addition to the fundamental importance of 
water, the relative irrelevancy of some other conditions 


usually deemed indispensable to organic existence 
there find illustration too. On the high plateau of 
northern Arizona and on the still higher volcanic cones 
that rise from them as a base into now disintegrating 
peaks, the thin cold air proves no bar to life. To the 
fauna there air is a very secondary consideration to 
water, and because the latter is scaree in the lowlands 
and more abundant higher up,, animals ascend after it, 
making their home at unusual elevations with no dis- 
comfort to themselves. Deer range to heights where 
the barometric pressure is but three fifths that of their 
generic habitat. Bear do the like, the brown bear of 
northern American sea-level being here met with two 
miles ;il)<>\e it. Nor is either animal a depauperate 
form. Man himself contrives to live in comfort and 
propagate his kind where at first he finds it hard to 
breathe. Nor are these valiant exceptions; as Mer- 
riam has ably shown in his account of the San Francisco 
peak region for the Smithsonian Institution a most in- 
teresting report, by the way the other animals are 
equally adaptive to the zones of more northern lati- 
tudes on the American continent, zones paralleled in 
their flora and fauna by the zones of altitude up this 
peak. All which shows that paucity of air is nothing 
like the barrier to life we ordinarily suppose and is not 
for in instant to be compared with dearth of water. 
If in a comparatively short time an animal or plant 

chap, ii A DEPARTURE-POINT 19 

accustomed to thirty inches of barometric pressure can 
contrive to subsist sensibly unchanged at eighteen, it 
would be rash to set limits to what time may not do. 
And this the more for another instructive fact discov- 
ered in this region by Merriam : that the existence of 
a species was determined not by the mean tempera- 
ture of its habitat but by the maximum temperature 
during the time of procreation. A short warm season 
in summer alone decides whether the species shall 
survive and flourish ; that it has afterward to hiber- 
nate for six months at a time does not in the least 
negative the result. 

That the point of departure should thus prove of 
twofold importance, speeding the observer on his 
journey and furnishing him with a vade mecum on 
arrival, is as curious as opportune. Without such 
furtherance, to the bodily eye on the one hand and 
the mind's eye on the other, the voyage were less con- 
clusive in advent and less satisfactory in attent. 



WITH Mars discovery has from the start waited on 
apparent disk. To this end every optical ad- 
vance has contributed from the time of Galileo's opera- 
glass to the present day. For apparent distance stands 
determined by the size of the eye. But although it 
is the telescopic eye that has increased, not the distance 
that has diminished, the effect has been kin to being 
carried nearer the planet and so to a scanning of its disk 
with constantly increasing particularity. Mankind has 
to all intents and purposes been journeying Marsward 
t hrough the years. Any historic account of the planet, 
therefore, becomes a chronicle of seeming bodily ap- 

Perhaps no vivider way of making this evident and 
at the same time no better preface to the present work 
could be devised than by putting before the eye in 
orderly succession the maps made of Mars by the lead- 
ing areographers of their day, since the planet first 
began to be charted sixty-five years ago. The pro- 
cedure is as much as possible like standing at the tele- 
scope and seeing the phenomena steadily disclose. 



Seen thus in order the facts speak for themselves. 
They show that from first to last no doubt concerning 
what was seen existed in the minds of those competent 
to judge by systematic study of the planet at first hand, 
and furthermore, from their mutual corroboration, that 
this confidence was well placed. For, far from there 
being any conflict of authorities in the case, those en- 
titled to an opinion in the matter prove singularly at 

Beginning with Maedler in 1840 the gallery of such 
portraitures of the planet comprises those by Kaiser, 
Green and Schiaparelli, continued since Schiaparelli's 
time by the earlier ones of the present writer. To 
this list has been added one by Flammarion, which 
though not solely from his own work gives so just a 
representation of what was known at the date, 1876, as 
to merit inclusion. The remarkable drawings of Dawes 
and the excellent ones of Lockyer in 1862-1864 were 
never combined into maps by the observers, and though 
the former's were so synthesized by Proctor in 1867, 
the result was conformed to what Proctor thought ought 
to be and so is not really a transcript of the drawings 

Each of the maps presented marked in its day the 
point areography had reached ; and each tells its own 
story better than any amount of text. They are 
all made upon Mercator's projection and omit in 


consequence the circumpolar regions. The later ones 
give, too, only so much of the surface as was shown at 
the opposition they record, for Mars, being tipped now 
one way, now another, regards the earth differently ac- 
cording to its orbital position. In comparing them, 
therefore, the equator must betaken for medial line. 
Mercator's projection has been the customary one for 
portraying Mars except for such oppositions as chiefly 
disclose the arctic pole. And this, too, with a certain 
poetic fitness. For it comes by right of priority to 
delineation of a new world; seeing that Mercator was 
the first to represent in a map the mundane new world 
in its entirety, by the rather important addition of 
North America to the southern continent already 
known, and to give the whole the title America with 
'Ame' at the top of the map and 'rica' at the bottom. 
In looking at the maps it is to be remembered that 
they are what we should call upside down, south stand- 
ing at the top and north at the bottom. Inverted they 
show because this is the way the telescopic observer al- 
ways sees the planet. The disk would seem unnatural 
to astronomers were it duly righted. Just the same do 
men in the southern hemisphere look at our own Earth 
topsy-turvy according to our view, the Sun being to 
the north of them and the cold to the south. Certain 
landmarks distinguishable in all the maps may serve for 
specific introduction. The Y-shaped marking on the 


equator pointing to the north is the Syrtis Major, the 
first marking ever made out upon the planet and drawn 
by the great Huyghens in 1659. The isolated oval 
patch in latitude 26 south is the Solis Lacus, the pupil 
of the eye of Mars; while the forked bay on the 
equator, discovered by Dawes, is the Sabaeus Sinus, 
the dividing tongue of which, the Fastigium Aryn, 
has been taken for the origin of longitudes on Mars. 

Twelve maps go to make the series. They are 
as follows: 

Maker Date 

I. Map of Beer and Maedler .... 1840 

II. " " Kaiser 1864 

III. " " Flammarion (Resume) . . 1876 

IV. " " Green 1877 

V. " " Schiaparelli 1877 

VI. " " " 1879 

VII. " " " 1881 

VIII. " " " 1884 

IX. " " Lowell 1894 

X. " " " 1896 

XL " " " 1901 

XII. " " " 1905 

If these maps be carefully compared they will be 
found quite remarkably confirmatory each of its prede- 
cessor. To no one will their inter-resemblance seem 
more salient than to draughtsmen themselves. For 
none know better how surprisingly, even when two 

24 MARS AM) ITS CANALS chap, m 

men have the same tiling under their very noses to copy, 
their two versions will differ. Judgment of position 
and of relative 4 size is one cause of variation; focusing 
of the attention on different details another. What 
slight discrepancies affect the maps are traceable to 
these two human imperfections. Maps IV and V 
make a case in point: it was to his new-found canals 
that Schiaparelli gave heed to the neglect of a due ton- 
ing of his map; while Green, less keen-eyed but more 
artistic, missed the delicate canaliform detail to make 
a speaking portraiture of the whole. 

Amid the remarkable continuity of progression here 
shown, in which each map will be seen to be at once a 
review and an advance, we may, nevertheless, distin- 
guish three stages in the perception of the phenomena. 
Thus we may mark : 

I. A period of recognition of larger markings 

only; . 1840-1877 

II. A period of detection of canals intersecting 

the bright regions or lands; .... 1877-1892 
III. A period of detection of canals traversing 
the 'seas' and of oases scattered over 
the surface; 1892-1905 

Each period is here represented by four charts; and 
each expresses the result of a more minute and intimate 
acquaintance with the disk than was possible to the one 
thai went before. To realize, however, how accurate; 


each was according to his lights it is only necessary 
to have the seeing grow steadily better some evening 
as one observes. He will find himself recapitulating 
in his own person the course taken by discovery for 
all those who went before, and in the lapse of an hour 
live through the observational experience of sixty 
years; in much the same way that the embryological 
growth of an individual repeats the development his- 
torically of the race. 

Two verses of Ovid, which .the poet puts into the 
mouth of Pythagoras, outline with something like 
prophetic utterance the special discoveries which mark 
the three periods apart. Ovid makes Pythagoras say 
of the then world : 

Vidi ego, quod fuerat quondam solidissima tellus 
Esse f return; vidi factas ex aequore terras; 

Ovid, Metamorphoses XV, 262. 

(Where once was solid ground I've seen a strait ; 
Lands I've seen made from out the sea.) 

True as the verses are of Earth, the poet could not have 
penned them otherwise had he meant to record the 
course of astronomic detection on Mars. For they 
sound like a presentiment of the facts. A surface 
thought at first to be part land, part water ; the land 
next seen to be seamed with straits ; and lastly the sea 
made out to be land. Such is the history of the sub- 
ject, and words could not have summed it more sue- 

26 MARS AND ITS CANALS chap, in 

cinctly. "Vidi ego, quod fuerat quondam solidissima 
tellus esse fretum " rings like Schiaparelli's own an- 
nouncement of the discovery of the 'canals.' Indeed, 
I venture to believe he would have made it had he 
chanced to recall the verse. So "vidi factas ex 
aequore terras" tells what has since been learned of 
the character of the seas. 

Of the three periods the first was that of the main or 
fundamental markings only. It came in with Beer 
and Maedler, the inaugurators of areography. That 
they planned and executed their survey with but a 
four-inch glass shows that there is always room for 
genius at the top of any profession and that instruments 
are not for everything in its instrumentality. Up to 
their day the reality of the planet's features had been 
questioned by some people in spite of having been 
certainly seen and drawn by Huyghens and others. 
Beer and Maedler's labors proved them permanent 
facts beyond the possibility of dispute. 

The second period was the period of the discovery of 
the now famous canals, a new era in the study of 
Mars opened by Schiaparelli in 1877 (Map V). Un- 
suspicious of what he was to stumble on, he seized the 
then favorable opposition to make, as he put it, a 
geodetic survey of the planet's surface. He hoped this 
undertaking feasible to the accuracy of micrometric 
measurement. His hopes did not belie him. He 

Map I. Beer and Maedler, 1840. 

Map II. Kaiser, 18t>4. 
(From Flammarion's Mars.) 

!Wf<vaJS l.^.t-""" 

Map III. Resume by Flaininarion, 1876. 
(From Flammarion's Mars.) 

Map IV. Green, 1877. 
(From Flammarion's Mars.) 


found that it vvas possible to measure his positions with 
sufficient exactness to :r lie a skeleton map on which 
to embody the markings in detail and thus to give 
his map vertebrate support. But in the course of his 
work he became aware of hitherto unrecognized liga- 
ments connecting the seas with one another. Instead 
of displaying a broad unity of face the bright areas 
appeared to be but groundwork for streaks. The 
streaks traversed them in all directions, tesselating the 
continents into a tile work of islands. Such mosaic was 
not only new, but the fashion of the thing was of a 
new order or kind. Straits, however, Schiaparelli con- 
sidered them and gave them the name canali, or chan- 
nels. How unfamiliar and seemingly impossible the 
new detail was is best evidenced by the prompt and 
unanimous disbelief with which it was met. 

Unmoved by the universal scepticism which rewarded 
what was to prove an epoch-making discovery, Schia- 
parelli went on, in the judgment of his critics, from bad 
to worse for in 1879 (Map VI) he took up again his 
scrutiny of the planet to the detecting of yet more par- 
ticularity. He re-observed most of his old canals and 
discovered half as many more ; and as his map shows 
he perceived an increased regularity in his lines. 

In 1881-1882 (Map VII) he attacked the planet again 
and with results yet further out of the common. His 
lines were still there with more beside. If they had 


looked strange before, they now appeared positively 
unnatural. Not content with a regularity which 
seemed to the sceptics to preclude their being facts, he 
must needs see them now in duplicate. To the eyes of 
disbelief this was the crowning stroke of factitiousness. 

In consequence no end of adverse criticism was 
heaped upon his observations by those who could not 
see. But curiously enough, what did not attract 
attention, the blindness of the critics was as much 
mental as bodily. For they failed to perceive that 
the very unnaturalness which seemed to them to dis- 
ci-edit his observations really proved their genuineness. 
His discoveries were so amazing that any change in 
strangeness simply went to confirm the universal scep- 
ticism and clouded logic. Yet properly viewed, a 
pregnant deduction stands forth quite clearly on a 
study of the maps. 

On comparing maps V, VI and VII an eye duly 
directed is struck by a difference in the aspect of tin 4 
lines. In his first map the 'canals' are depicted sim- 
ply as narrow winding streaks, hardly even roughly 
regular and by no means such departures from the 
plausible as to lie without the communicatory paid 
Indeed, to a modern reader prepared beforehand for 
geometric construction they will probably appear no 
'canals' at all. Certainly the price of acceptance was 
not a large one to pay. But like that of the Sibylline 

Map V. Schiaparelli, 1877. 
(From Schiaparelli's Memoria.) 


Map VI. Schiaparelli, 1879. 
(From Schiaparelli's Memoria.) 

Map VII. Schiaparelli, 1881. 
(From Schiaparelli 's Memoria.) 

Map VIII. Schiapari-lli, 1884. 
(From Schiaparelli's Memoria.) 


Books it increased with putting off. What he offered 
the public in 1879 was much more dearly to be bought. 
The lines were straighter, narrower, and in every way 
less natural than they had seemed two years before. 
In 1881-1882 they progressed still more in unaccount- 
ability. They had now become regular rule and com- 
pass lines, as straight, as even, and as precise as any 
draughtsman could wish and quite what astronomic 
faith did not desire. Having thus donned the char- 
acter, they nevermore put it off. 

Now, this curious evolution in depiction points, 
rightly viewed, to an absence of design. It shows that 
Schiaparelli started with no preconceived idea on the 
subject. On the contrary, it is clear that he shared to 
begin with the prevailing hesitancy to accept anything 
out of the ordinary. Nor did he overcome his reluc- 
tance except as by degrees he was compelled. For the 
canals did not change their characteristics from one 
opposition to another; the eye it was that learned to 
distinguish what it saw, and the brain made better 
report as it grew familiar with the messages sent it. 
In other words, it is patent from these successive maps 
that the geometrical character of the 'canals' was 
forced upon Schiaparelli by the things themselves, 
instead of being, as his critics took for granted, foisted 
on them by him. We have since seen the regularity 
of the canals so undeniably that we are not now in need 


of such inferential support to help us to the truth ; but 
too late, as it is, to be of controversial moment the de- 
duction is none the less of some corroboratory force. 

With the third period enters what has been done since 
Schiaparelli's time. For that master was obliged, 
from failing sight, to close his work with the opposition 
of 1890. In 1892 W. H. Pickering at Arequipa was the 
chief observer of the planet and made two important 
discoveries : one was the detection of small round spots 
scattered over the surface of the planet and connected 
with the canal system; the other the perception of 
what seemed to him more or less irregular lines travers- 
ing the Mare Erythraeum. Both were notable detec- 
tions. The first set of phenomena he called lakes, 
the second river-systems, sometimes schematically 
canals/ but without committing himself to canaliform 
characteristics as his drawings make clear. The same 
phenomena were seen at that opposition at the lark, 
by Schaeberle, Barnard and others, and called streaks. 
These discoveries took from the maria their supposed 
character of seas a most important event in 
knowledge of Mars. 

The next advance was the detection at Flagstaff 
in 1894 of their canaliform characteristics by my then 
nit Mr. Douglass, who in place of the irregu- 
lar streaks and river-systems of his predecessors 
found the seas to be crossed by lines as regular and 

Map IX. Lowell, 1894. 

Map X. Lowell, 1896. 

Map XI. Lowell, 1901. 

Map XII. Lowell, 1905. 


as regularly connected as the canals in the light 
regions. To him they appeared broad and ill 
defined, but so habitually did to him the canals in the 
light areas, while for directness and uniformity the one 
set showed as geometrically perfect as the other. All 
the dark maria of the. southern hemisphere he found to 
be laced with them and that they formed a network 
over the dark regions, counterparting that over the 
light. Still more significant was the fact that their 
points of departure coincided with the points of arrival 
of the bright-region canals, so that the two connected 
to form in its entirety a single system. After the pub- 
lication of his results (Lowell Observatory Annals ; 
Volume I, 1895) Schiaparelli identified some of those 
in the Syrtis with what he had himself seen there in 
1888 (Memoria, VI, 1899), though his own had not been 
sufficiently well seen of him to impress him as canals. 
Of other additions to our knowledge since made by 
the writer the present book treats; as also of the 
theory they originally suggested to him and which his 
later observations have only gone to confirm. 



A LMOST as soon as magnification gives Mars a 
-*"*- disk that disk shows markings, white spots crown- 
ing a globe spread with blue-green patches on an orange 
ground. The smallest telescope is capable of this far- 
off revelation ; while with increased power the picture 
grows steadily more articulate and full. With a two 
and a quarter inch glass the writer saw them thirty-five 
years ago. 

Alter the assurance that markings exist the next 
thing to arrest attention is that these markings move. 
The patches of color first made out by the observer are 
shortly found by him to have shifted in place upon the 
planet. And this not through mistake on his part but 
through method in the phenomena ; for all do it alike. 
In. orderly rotation the features make their appearance 
upon the body's righthand limb (in the telescopic 
image), travel across the central meridian of the disk 
and vanish over its lefthand border. One follows an- 
other, each rising, culminating and setting in its turn 
under the observer's gaze. A constantly progressing 
panorama passes majestically before his sight, new 


chap, iv THE POLAR CAPS 33 

objects replacing the old with a march so steady and 
withal so swift that a few minutes will suffice to mark 
unmistakably the fact of such procession. But for 
all this ceaseless turning under his gaze, after a certain 
lapse of time it is evident that the same features are 
being shown him over again. With such recognition 
of recurrence comes the first advance toward acquaint- 
ance with the Martian world. For that in all their 
journeying their configuration alters not, proves them 
permanent in place, part and parcel of the solid surface 
of that other globe. This surface, then, lies exposed 
to view and by its turning shows itself subject, like 
our earth, to the vicissitudes of day and night. 

In such self-exposure Mars differs from all the four 
great planets, Jupiter, Saturn, Uranus and Neptune. 
Features, indeed, are apparent on the first two of these 
globes and dimly on the other two as well, but they lack 
the stability of the Martian markings. They are forever 
exchanging place. In the case of Jupiter what we see is 
undoubtedly a cloud-envelop through which occasional 
glimpses may possibly be caught of a chaotic nucleus 
below. With Saturn it is the same ; and the evidence 
is that the like is true of Uranus and Neptune. What 
goes on under their great cloud canopies we can only sur- 
mise. With Mars, however, we are not left to imagina- 
tion in the matter but so far as our means permit can 
actually observe what there takes place. Except for 

34 MARS AND ITS CANALS chap, iv 

distance, which, through science, year by year grows 
less, it is as if we hovered above the planet in a bal- 
loon, with its various features spread out to our gaze 

Attention shows these areographic features to be on 
hand with punctual precision for their traverse of the 
disk once every twenty-four hours and thirty-seven 
minutes. For over two hundred years this has been 
the case, their untiring revolutions having been watched 
so well that we know the time they take to the nicety 
of a couple of hundredths of a second. We thus become 
possessed of a knowledge of the length of the Martian 
day and it is not a little interesting to find that it very 
closely counterparts in duration our own, being only 
one thirty-fifth the longer of the two. We also find 
from the course the markings pursue the axis about 
which they turn; and just as the period of the rotation 
tells us the length of the Martian day so the tilt of the 
axis, taken in connection with the form of the orbit, 
dct ermines the character of the Martian seasons. Here 
again we confront a curious resemblance in the cir- 
cumstances of the two planets, for the tilt of the equator 
to the plane of the orbit is with Mars almost precisely 
what it is for the Earth. The more carefully the two are 
measured the closer the similitude becomes. Sir William 
rlerschel made the Martian 28, Schiaparelli reduced 
this to 25, and later determination by the writer 

chap, iv THE POLAR CAPS 35 

puts it nearer 24. The latter is the one now adopted 
in the British Nautical Almanac for observers of 
the planet. This is a very close parallelism indeed; 
so that in general character the Martian seasons 
are nearly the counterpart of ours. In length, how- 
ever, they differ; first because the year of Mars is 
almost double the length of the terrestrial one and 
secondly because from the greater ellipticity of Mars' 
orbit the seasons are more unequal than is the case with 
us, some being run through with great haste, others 
being lingered on a disproportionate time. It is usual 
on the Earth to consider spring as the period from the 
vernal equinox, about March 21, to the summer solstice, 
about June 20 ; summer as lasting thence to the au- 
tumnal equinox; autumn from this latter date, about 
September 20, to the winter solstice on December 21 ; 
and winter from that point on to the next spring 
equinox again. On this division our seasons in the 
northern hemisphere last respectively : spring, 91 days; 
summer, 92 days; autumn, 92 days; and winter, 90 
days. On Mars these become, reckoned in our days : 
spring, 199 days; summer 183 days; autumn, 147 
days; and winter, 158 days. If we had counted them 
in Martian days they would have totaled about one 
thirty-fifth less in number each. 

In its days and seasons, then, Mars is wonderfully 
like the Earth ; except for the length of the year we 


should hardly know the difference in reckoning of time 
could we some morning wake up there instead of here. 
Only in one really unimportant respect should we feel 
strange; in months we should find ourselves turned 
topsy-turvy. But lunations have nothing to do with 
climate nor with the alternation between night and 
day; and in these two important respects we should 
certainly feel at home. 

Though the axis could be determined by the daily 
march of any marking and thus the planet's tropic, 
temperate and polar regions marked out, the process 
is made easier by the presence of white patches cov- 
ering the planet's poles and known, in consequence, 
as the polar caps. It is from measures of the patches 
that the position of the Martian poles has actually 
been determined. These polar caps are exactly analo- 
gous in general position to those which bonnet our own 
Earth. They reproduce the appearance of the ice and 
snow of our arctic and antarctic regions seen from space, 
in a very remarkable manner. In truth they arc things 
of note in more ways than one and would claim prece- 
dence on many counts. Priority of recognition, how- 
ever, alone entitles them to premier consideration. 
Among the very first of the disk's detail to be made 
out by man, they justly demand description first. 

With peculiar propriety the polar caps have thus 
the pas. Not only do they stand first in order of 

chap, iv THE POLAR CAPS 37 

visibility, but they prove to occupy a like position 
logically when it comes to an explanation of the 
planet's present physical state. It is not matter of 
hazard that the most evident of all the planet's mark- 
ings should also be the most fundamental, the fountain- 
head from which everything else flows. It is of the 
essence of the planet's condition and furnishes the key 
to its comprehension. The steps leading to this con- 
clusion are as interesting as they are cogent. They 
start at the polar caps' visibility. For their size first 
riveted man's attention and then attention to them 
disclosed that most vital of the characteristics of the 
planet's surface: change. 

Just as almost all of the features we note are per- 
manent in place, showing that they belong to the surface, 
so are they all impermanent in character. Change 
is the only absolutely unchanging thing except position 
about the features the planet presents to view. It 
was in the aspect of the polar caps that this important 
fact first came to light. Not only did they thus initially 
instance a general law, they have turned out to make 
it; for by themselves changing they largely cause 
change in all the rest. But for a long time they alone 
exemplified its workings. (To Sir William Herschel 
we owe the first study of their change in aspect. This 
eminent observer noted that their varying size was 
subject to a regular rhythmic wax and wane timed to 

38 MARS AND ITS CANALS ohap. it 

the course of the seasons of the planet's year. The 
caps increased in the winter of their hemisphere and 
decreased in its summer and being situate in opposite 
hemispheres they did this alternately with pendulum- 
like precision. His observations were soon abundantly 
confirmed, for the phenomena take place upon a vast 
scale and are thus easy of recognition. ^U their maxi- 
mum spread the caps cover more than one hundred times 
as much ground as when they have shrunk to their 
minimum. In the depth of winter they stretch over 
much more than the polar zone, coming down to 60 
and even 50 of latitude north or south as the case may 
be, thence melting till by midsummer they span only 
five or six degrees across.) 

In this they bear close analogue to the behavior 
of our own. Ours would show not otherwise were they 
viewed from the impersonal standpoint of space. Very 
little telescopic aid suffices to disclose the Martian polar 
phenomena in this their more salient characteristics 
and convince an observer of their likeness to those of the 
earth. Any one may note what is there going on by 
successive observations of the planet with a three-inch 
glass. Nor is the change by any means slow. A few 
days at the proper Martian season, or at most a couple 
of weeks, produces conspicuous and conclusive altera- 
tions in the size of these nightcaps of the planet's 
winter sleep. Resembling our own so well they were 

chap, iv THE POLAR CAPS 39 

early surmised to be of like constitution and composed, 
therefore, of ice and snow. Plausible on its face, this 
view of them was generally adopted and common sense 
has held to it ever since. It has encountered, of course, 
opposition, partly from very proper conservatism, 
but chiefly from that earth-centred philosophy which 
has doubted most advances since Galileo's time, and 
carbonic acid has been put forward by this school of 
sceptics to take its place. We shall critically examine 
both objections; the latter first, because a certain 
physical fact enables us to dispose of it at once. (In 
casual appearance there is not much to choose between 
the rival candidates of common sense and uncommon 
subtlety, water and frozen carbonic acid gas, both being 
suitably white and both going and coming with the 
temperature. But, upon closer study, in one point of 
behavior the two substances act quite unlike, and had 
half the ingenuity been expended in testing the theory 
as in broaching it this fact had come to light to the 
suggestors as it did upon examination to the writer 
and had served as a touchstone in the case. At pres- 
sures of anything like one atmosphere or less carbonic 
acid passes at once from the solid to the gaseous state. 
Water, on the other hand, lingers in the intermediate 
stage of a liquid. Now, as the Martian cap melts it 
shows surrounded by a deep blue band which accom- 
panies it in its retreat, shrinking to keep pace with the 

40 MARS AND ITS CANALS chap, iv 

shrinkage in the cap. This is clearly the product of the 
disintegration since it waits so studiously upon it. The 
substance composing the cap, then, does not pass in- 
stantaneously or anything like it from the solid to the 
gaseous condition. 

This badge of blue ribbon about the melting cap, 
therefore, conclusively shows that carbonic acid is 
not what we see and leaves us with the only alternative 
we know of : water J 



\ SSURED by physical properties that our visual 
appearances are quite capable of being what they 
seem we pass to the phenomena of the cap itself. Like 
as are the polar caps of the two planets at first regard, 
upon further study very notable differences soon dis- 
close themselves between the earthly and the Martian 
ones; and these serve to give us our initial hint of a 
different state of things over there from that with 
which we are conversant on Earth. 

To begin with, the limits between which they fluc- 
tuate are out of all proportion greater on Mars. It is 
not so much in their maxima that the ice-sheets of the 
two planets vary. Our own polar caps are much 
larger than we think; indeed, we live in them a good 
fraction of the time. Our winter snows are in truth 
nothing but part and parcel of the polar cap at that 
season. Now, in the northern hemisphere snow covers 
the ground at sea-level more or less continuously down 
to 50 of latitude. It stretches thus far even on the 
western flanks of the continents, while in the middle of 
them and on their eastern sides it extends ten degrees 



farther yet during the depth of winter. So that we 
have a polar cap which is then ninety degrees across. 
In our southern hemisphere it is much the same six 
months later, in the corresponding winter of its year. 
On Mars at their winter maxima the polar caps extend 
over a similar stretch of latitude. They do so, how- 
ever, unequally. The southern one is considerably the 
larger. In 1903, 136 days after the winter solstice, 
in the Martian calendar February 27, it came down in 
longitude 225 to 44 of latitude and may be taken to 
have then measured ninety-three degrees across; in 
1905, 121 days after the same solstice, it stretched 
in longitude 235 to latitude 42, and 158 days later, 
in longitude 221 to latitude 41; values which, sup- 
posing it to have been round, imply for it a diameter 
on these occasions of ninety-six and ninety-seven 
degrees. It was then February 20 and March 10 
respectively of the Martian year. These determinat ions 
of its size at the two oppositions agree sufficiently well 
considering the great tilt away from us of the south 
pole at the time and the horizonward foreshortening 
of the edge of the snow. It seems from a consensus 
of the measures to have been some five degrees 
wider in 1903 than in 1905, which may mean a colder 
winter preceding the former date. The cap was still 
apparently without a dark contour in both years, 
showing that it had not yet begun to melt. 

South Polar Cap. 
(Lowell Observatory, 1905.) 


Less has been learnt of the northern cap. In 1896- 
1897 when it was similarly presented skirting the other 
rim of the disk, a gap occurred in the observations corre- 
sponding to the time by Martian months between Feb- 
ruary 24 and March 22. On the former date the cap 
came down only to latitude 55 in longitude 352; 
on the subsequent one and for several days after the 
latitude of the southern limit of the snow was such as 
to imply a breadth to it of about eighty degrees. The 
cap was now bordered by a dark line, proving that melt- 
ing had already set in. It cannot, however, at its 
maximum have covered much more country than this, 
in view of its lesser extent on February 24. 

Fair as our knowledge now is of the dimensions of the 
Martian polar caps at their maxima, we have much 
more accurate information with regard to their minima, 
and this, too, was obtained much earlier. That we 
should first have known their smallest rather than their 
greatest extent with accuracy may appear surprising, 
exactly the opposite being our knowledge of our own. 
It is not, however, so surprising as it appears, inas- 
much as it is an inevitable consequence of the planet's 
aspect with regard to the sun. When the tilt of the 
axis inclines one hemisphere toward the sun, that hemi- 
sphere's polar cap must melt and dwindle, while at 
the same time it is the one best seen, the other being 
turned away from the sun and therefore largely 

44 MARS AND ITS CANALS , map. v 

from us as well ; so that even such part of the latter 
as is illumined lies low down toward the horizon of 
the disk where a slight change of angle means a 
great difference in size. 

It has thus come about that both the south and the 
north polar caps have been repeatedly well seen and 
measured at their minimum; and the measures for 
different Martian years agree well with one another. 
For the northern cap six degrees in diameter is about 
the least value to which it shrinks. The south one 
becomes even smaller, being usually not more than five 
degrees across, while in 1894 it actually vanished, a 
thing unprecedented. Its absence was detected by 
Douglass at Flagstaff and shortly after the announce- 
ment of its disappearance the fact was corroborated 
by Barnard at the Lick. The position the cap would 
have occupied was at the time better placed for obser- 
vation in America than in Europe, inasmuch as the 
cap is eccentrically situated with regard to the geo- 
graphic pole and its centre was then well on the side 
of the disk presented to us while in Europe it was turned 
away. This, together with the fact that it undoubtedly 
came and went more than once about this time, ac- 
counts for its disappearance not having been recog- 
nized there, haze left by it having apparently been 
mistaken for the cap itself. 

On Earth the minima are much larger. In the 

North Polar Cap. 
(Lowell Observatory, 1905.) 


northern hemisphere the line of perpetual snow or 
pack-ice in longitude 50 east runs about on the 80 
parallel, including within it the southern end of Franz 
Joseph Land. Opposite this, in longitude 120 west, 
above the North American continent, it reaches down 
lower still to 75. So that the cap is then from twenty 
to thirty degrees in diameter. In the southern hemi- 
sphere it is even larger. In longitude 170 west the 
land was found by Ross to be under perpetual snow in 
latitude 72. Cook had reached in longitude 107 
east an impassable barrier of ice in latitude 70 23'. 
The season was then midsummer, January 30. So that 
we are perhaps justified in considering 71 south as 
about the average limit of perpetual snow or paleo- 
crystic ice. This would make the southern cap at its 
minimum thirty-eight degrees across. Pack-ice with 
open spots extends still farther north. The Pagoda in 
1845 was stopped by impenetrable pack-ice in south 
latitude 68 and the Challenger in 1874 encountered 
the pack in latitude 65 on the 19th of February, which 
corresponds about to our 19th of August, the time at 
which the sea should be most open. The limit of per- 
petual snow is thus lower in the southern than in the 
northern hemisphere. Here again, then, the two 
minima differ, but in the reverse way from what they 
do on Mars. 

From this we perceive that the variations in size of 


the caps arc much more striking on Mars than on the 
Earth and that these arc due chiefly to the difference in 
the minima, the maxima not varying greatly. 

To explain these interesting diversities of behavior 
in the several polar caps we shall have to go back a 
little in general physics in order to get a proper take 
off. It is a curious concomitant of the law of gravity 
that the amount of heat received by a planet in passing 
inuu any point of its path to a point diametrically 
opposite is always the same no matter what be the 
eccentricity of the orbit. Thus, a planet has as many 
calorics falling upon it in travelling from its vernal 
equinox to its autumnal as from the autumnal to the 
vernal again, although the time taken in the one journey 
Im very different from that of the other. This is due 
to the fact that the angle swept over by the radius vec- 
tor, that is, the imaginary bond between it and the sun, 
is at all points proportional to the amount of heat re- 
ceived; just as it is of the gravity undergone, the two 
forces radiating into space as the inverse square of the 
distance. Thus the heat received by a point .or a 

lisphere, through any orbital angle, is independent 
of the eccentricity of the orbit. 

s not independent of the axial tilt. For the 

' "t the sun's rays is modified by their obliquity. 

mount of heat received at any point in consequence 

turns upon the position of the point, and for 


any hemisphere taken as a whole it depends upon the 
degree to which the pole is tilted to the source of heat. 
In consequence of being more squarely presented to its 
beams, the hemisphere which is directed toward the 
sun and therefore is passing through its summer season 
gets far more insolation than that which is at the same 
time in the depth of its winter. For a tilt of twenty- 
four degrees, the present received value for the axis 
of Mars, the two hemispheres so circumstanced get 
amounts of heat respectively in the proportion of 
sixty-three to thirty-seven. 

But, though the summer and winter insolation thus 
differ, they are the same for each hemisphere in turn. 
Consequently the mere amount of heat received cannot 
be the cause of any differences detected between the 
respective maxima and minima of the two polar 
caps. If heat were a substance which could be stored 
up instead of being a mode of motion, the effect pro- 
duced would be in accordance with the quantity ap- 
plied and the two caps would behave alike. As it is 
the total amount has very little to say in the matter. 

Not the amount of heat but the manner in which this 
heat is made at home is responsible for the difference 
we observe. Now, though the total amount is the 
same in passing from the vernal to the autumnal equinox 
as from the autumnal to the vernal, the time during 
which it is received in either case varies from one hemi- 


sphere to the other. It is summer in the former while 
it is winter in the latter and tin 4 difference in the length 
of the two seasons due to the eccentricity of the orbit 
makes a vast difference in the result. Winter affects 
the maxima, summer the minima, attained. Of these 
opposite variations presented to us by the two caps, 
the maxima, the one most difficult to detect, is the 
easiest to explain, for the difference in the maxima 
seems to be due to the surpassing length of the antarctic 

Owing to the eccentricity of the orbital ellipse pur- 
sued by Mars and to the present position of the planet's 
solstices, the southern hemisphere is farther away from 
the sun during its winter and is so for a longer time. 
The seasons are in length, for the northern hemisphere: 
spring 199 days; summer, 183 days; autumn, 147 
days; and winter. 158 days; while for the southern 
hemisphere they are : spring, 147 days; summer, 158 
days; autumn. 199 days; and winter, 183 days. The 
arctic polar night is thus 305 of our days long; the 
antic. 382. Thus for 77 more days than happens to 
fellow the southern pole never sees the- sun. Now, 
the total sunlight from equinox to equinox is the 
ii Imth hemispheres, its distribution by days must 
rent. In the southern hemisphere the same 
'int is crowded into a smaller compass in the 
proportion of 305 to 382 : thai being that hemisphere's 


relative ratio of days. But since during winter the cap 
increases, there is a daily excess of accumulation over 
dissipation of snow and each twenty-four hours must 
on the average add its tithe to the sum total. Since the 
northern days are the warmer each adds less than do 
the southern ones ; and furthermore there are fewer of 
them. On both these scores the amount of the dep- 
osition about the northern pole should be less than 
about the southern one. Consequently, the snow- 
sheet there should be the less extensive and show a 
relatively smaller maximum, which explains what we 

With the minima the action is otherwise. Inasmuch 
as the greater heat received during the daylight hours 
by the southern hemisphere is exactly offset by the 
shortness of its season, it would seem at first as if there 
could be no difference in the total effect upon the two 

But further consideration discloses a couple of factors 
which might, and possibly do, come in to qualify the 
action and account for the observed effect. One is that 
though the total amount of heat received is the same, 
the manner of its distribution differs in the two hemi- 
spheres. In the northern one the time from vernal 
to autumnal equinox is 382 days against 305 in the 
southern. Consequently, the average daily heat is 
then five fourths more intense in the southern hemi- 


sphere. Indeed, it is even greater than this and nearer 
four thirds, because the melting occurs chiefly in the 
spring and in the first two months of summer when the 
contrast in length of season between the two hemi- 
spheres is at its greatest. Now, a few hotter days 
might well work more result than many colder ones. 
And this would be particularly true of Mars where the 
mean temperature is probably none too much above the 
freezing-point to start with. Ice consumes so much 
calorie in the process of turning into any other state, 
laving it by in the form of latent heat before it can 
turn into water and then so much more before this 
water can be converted into steam that a good deal has 
to be expended on it before getting any perceptible 
result. Once obtained, however, the heat is retained 
with like tenacity. So that the process works to 
double effect ! If sufficient heat be received the ice is 
first melted, then evaporated and finally formed into 
a layer of humid air, the humidity of which keeps it 
warm. Dry air is unretent ive of heat, moist air the 
opposite. And for the melting of the ice-cap to pro- 
ceed most effectively the temperature that laps it about 
niu>t be as high as possible and kept so as continuously 
as may be. If between days it be allowed to fall too 
low at night much caloric must needs be wasted in 
simply raising the ice again to the melting-point. This 
a blanket of warm air tends to prevent, and this again 


is brought about by a few hot days rather than by 
many colder ones. It is not all the heat received that 
becomes effective but the surplus heat above a certain 
point. The gain in continuity of action thus brought 
about is somewhat like that exhibited between the 
running of an express and an accommodation train. 
To reach its destination in a given time the former 
requires far less power because it does not have to get 
up speed again after each arrest. Thus the whole effect 
in melting the snow would be greater upon that hemi- 
sphere whose summer happens to be the more intense. 
The greater swing in size of the cap most exposed to 
the effects of the eccentricity is, then, the necessary 
result of circumstances when the precipitation is not 
too great to be nearly carried off by the subsequent 
dissipation. This is the state of things on Mars and 
the second of the factors above referred to. On the 
Earth as we have seen the polar caps are somewhat 
larger at their maximum and very much so at their 
minimum. Now, this is just what should happen 
were the precipitation increased. Suppose, for exam- 
ple, that the amount of precipitation were to increase 
while the amount of summer melting remained the 
same, and this would be the case if the vapor in the air 
augmented for one cause or another, and the result 
of each fresh deposit was locked up in snow. After 
a certain point the cap would grow in depth rather than 


in extension; the winter deposit would be thicker 
but the summer evaporation would remain the same. 
.\>w. if this occurred, it is evident that the minimum 
size of the cap would increase relatively much faster 
than the maximum, and furthermore, that the relative 
increase of the minimum in the two caps would be 
greatest for that which had seasons of extremes. 
The result we see in the case of the Earth. In the arctic 
cap, where in consequence of the eccentricity of the 
orbit the winter is shorter, the maximum is less than 
in the antarctic and this extra amount of precipitation 
cannot be wholly done away with in its intenser sum- 
mer, so that the minimum too is greater there. 

We reach, then, this interesting conclusion. We find 
that eccentricity of orbit by itself not only causes no 
universal glaciation in the hemisphere w T hich we should 
incidentally suppose likely to show it, but actually 
produce.- the opposite result, in more than offsetting by 
summer proximity what winter distance brings about. 
To cause extensive glaciation we must have, in addi- 
tion to favorable eccentricity, a large precipitation. 
W it li these two factors combined we get an ice age, but 
not otherwise. The result has an important bearing 
on geologic glacial periods and their explanation. 

Once formed, an ice-sheet cools everything about it 
and chills the climate of its hemisphere. It is a per- 
|Mtual storehouse of cold. Mars has no such general 


glaciation in either hemisphere, and the absence of it, 
which is due to lesser precipitation, together with the 
clearness of its skies, accounts for the warmth which 
the surface exhibits and which has been found so hard 
hitherto to interpret. Could our earth but get rid of 
its oceans, we too might have temperate regions 
stretching to the poles. 



I y >LAR expeditions exert an extreme attraction on 
certain minds, perhaps because they combine the 
maximum of hardship with the minimum of head- 
way. Inconclusiveness certainly enables them to be 
constantly renewed, without loss either of purpose or 
prestige. The fact that the pole has never been trod 
by man constitutes the lodestone to such undertakings; 
and that it continues to defy him only whets his en- 
deavor the more. Except for the demonstration of the 
|M)lar drift-current conceived of and then verified by 
Nanscn, very little has been added by them to our 
knowledge of the globe. Nor is there specific reason to 
supposethat what theymight add would be particularly 
vital. Nothing out of the way is suspected of the pole 
beyond the simple fact of being so positioned. Yet 
for their patent inconclusion they continue to be sent 
in sublime superiority to failure. 

lian polar expeditions, as undertaken by the 
itronomer, are the antipodes of these pleasingly peril- 
ous excursions in three important regards, which if 
; appealing to the gallery commend themselves to the 


philosopher. They involve comparatively little hard- 
ship ; they have accomplished what they set out to do ; 
and the knowledge they have gleaned has proved funda- 
mental to an understanding of the present physical 
condition of the planet. 

The antithesis in pole-pursuing between the two 
planets manifests itself at the threshold of the inquiry, 
in the relative feasibility with which the phenomena 
on Mars may be scanned. For, curiously enough, in- 
stead of being the pole and its surrounding paleo- 
crystic ice which remains hidden on Mars, it is rather the 
extreme extent of its extension and the lowest latitu- 
dinal deposit of frost which lies shrouded in mystery. 
The difficulty there is not to see the pole but to see in 
winter the regions from which our own expeditions set 
out. And this because the poles are well displayed 
to us at times which are neither few nor very far be- 
tween ; while favorable occasions for marking the edge 
of the caps when at their greatest have neither proved 
so numerous nor so favorable. The tilt of the planet's 
axis when conveniently placed for human observation 
has been the cause of the one drawback ; the planet's 
meteorological condition in those latitudes at that 
season the reason for the other. 

What knowledge we have of the size of the caps in 
degrees upon the surface of the planet at this their 
extreme equatorward extension has been given in the 


last chapter. Their aspect at the time together with 
what that aspect betokens was not there touched upon. 
With it, therefore, and the peculiarities it presents to 
view we shall begin our account of the caps' annual 

When first the hemisphere, the pole of which has for 
half a Martian year been turned away from the sun, 
begins to emerge from its long hibernation, the snow- 
cap which covers it down even to temperate regions 
presents an undelimited expanse of white, the edges 
of which merge indistinguishably into the groundwork 
color of the regions round about. Of a dull opaque 
hue along its border, its contour is not sharp but fades 
off in a fleecy fringe without hard and fast line of de- 
marcation. Such notably was the aspect of the north 
temperate zone in 1896 when, tilted as it then was away 

from us into a mere northern 
horizon of the planet's limb, 
it showed prior to tin 1 definite 
recognition of the north polar 
cap in August of that year, 
and such too was the look of 
the disk's southern edge both 
before and after the first cer- 
tain detection of the south- 
' IBM and 1905. Each was then in the depth 
of winter. For in Martian chronology the season cor- 

SmdiIi I'nlfir ('ap in winter. 


responded in each at the time to what we know in our 
northern hemisphere as the latter part of February 
and the early part of March and the appearance of the 
planet's surface in both was not unlike what we know 
at the same season in latitude 45. Indeed, there is 
reason to suppose bad weather there then and the 
extreme fringe, from the pale tint it exhibited, to have 
been cloud rather than snow. 

It is quite in keeping with what we know on earth 
or can conceive of elsewhere that such aspect should 
characterize the cap at or near the attainment of its 
greatest development. Whether it were not yet quite 
arrived at this turning-point of its career or had but 
slightly passed it a vagueness of outline would in either 
event proclaim the fact. For were the frost still de- 
positing, the cap's edge would show indefinite ; and on 
the other hand had it just begun to melt, evaporation 
would give it an undefined edge before the melting 
water had gathered in sufficient quantities to be itself 

Its behavior subsequent to recognition bore out the 
inference from its aspect when it first appeared. While 
for many days prior to its coming unmistakably into 
view it was impossible to say whether what was seen 
of the southern cap in 1903 and 1905 was cloud or 
snow; so even after it had definitely disclosed itself it 
continued to play at odds with the observer. Showing 


sharp at the edges one clay it would appear but hazily 
defined the next, thus clearly demonstrating itself to be 
at the then unstable acme of its spread. Such a state 
of things we are only too familiar with in our own 
March weather when after days of sunshine that have 
melted off the winter's white and fringed it with rivulets 
and awakening grass, a snow-storm falling upon it pow- 
ders the ground again that was beginning to be bare 
ami at one stroke extends the domain of the snow while 
mystifying the actual limits it may be said to occupy. 
The same condition of things, then, is not unknown on 
Mars, and to fix the precise date of so wavering a phe- 
nomenon is not so much matter of difficult observation 
as of physical impossibility. 

Nor is the southern cap, at this the height of its 
winter expansion, confined strictly to its own proper 
limits. Faint extensions, now so connected with its 
main body as to form part and parcel of it, now so de- 
tached and dull of tint as to make the observer doubt- 
ful of the exact relationship, are generally to be seen 
ttendant <>n it. Hellas in winter is much given to such 
questionable garb, and has in consequence been mis- 
by more than one observer for the cap itself, 
\l as it does well upon the southern limb and 
: often the only region to show white. Indeed, 
-bound as it then is, to consider it the polar cap, 
possibly geographically incorrect, may cli- 



Hellas in winter. 

matologically be sustainable. Its northern extremity 
extends down to latitude 30 , a pretty low latitude 
for frost. Still such equator- 
ward extension is not with- 
out corroborating parallel. 
In 1903, at what was in 
Martian dates April 26, the 
whole of the region south of 
the Solis Lacus and the 
Nectar showed white, with a 
whiteness which may as well 
have been hoarfrost as cloud. Now, the Nectar runs 
east and west in latitude 28. So that in this in- 
stance, too, it is possible that 
arctic conditions knocked at 
the very doors of the tropics. 
Encroachment of the sort is 
equivalent to snow in Cairo 
and permanent snow at that ; 
not an occasional snow flurry, 
but something to linger on 
the ground and stay visible 
sixty millions of miles away. 
Knowledge of either cap in this the midwinter of its 
year has been a matter of the most recent oppositions 
of the planet. Up to within the last few years our 
acquaintance with either cap was chiefly confined to the 

White south of Nectar and 
Solis Lacus. 


months, one might almost say the weeks, imme- 
diately surrounding the summer solstice of its respec- 
tive hemisphere. The behavior of the caps during the 
rest of their career was largely unknown to us, from 
the very disadvantageous positions they occupied at the 
times the planet was nearest to the earth. Beginning 
with 1894, however, our knowledge of both has been 
much extended, by a proportionate extension of the 
period covered by the observations. It used to be 
thought impracticable to observe the planet far on 
either side of opposition; now it is observed from as 
much as four months before that event to the same 
period after it. The result is a systematic series of ob- 
servations which in many ways has given unexpected 
insight into Martian conditions. One of the benefits 
secured has been the lengthening of the period of study 
of the cap's career, a pushing of inquiry farther back 
into its spring history and a longer lingering with it 
in it< autumnal rebuilding. Yet up to the very last 
opposition a gap in its chronology still remained be- 
tween February 25 and April 1. The opposition of 
P.M).*) has bridged this hiatus and brought us down to 
the latter date, at which the melting of the cap begins 
in earnest. 

'his point, April 1 on, we have abundant evi- 

the cap's behavior. Its career now for some 

h one long chronicle of contraction. Like Bal- 


zac's Peau de Chagrin it simply shrinks, giving out of its 
virtue in the process. The cap proceeds to dwindle 
almost under the observer's eye till, from an enor- 
mous white counterpane spread over all the polar and 
a large part of the temperate zone, its area contracts 
to but the veriest nightcap of what it was before. 
From seventy degrees across it becomes sixty, then 
fifty, then forty, till by the middle of the Martian 
May it has become not more than thirty degrees in 
diameter. During this time, from the moment the 
melting began in good earnest, the retreating white 
is girdled by a dark band, of a blue tint, which 
keeps pace with the edge of the cap, shrinking as it 
shrinks, and diminishing in width as the volume of 
the melting decreases) 

After the melting has been for some time under way 
and the cap has become permanently bordered by its 
dark blue band a peculiar phenomenon makes its 
appearance in the cap itself. This is its fission into one 
or more parts. The process begins by the appearance 
of dark rifts which, starting in from the cap's exterior, 
penetrate into its heart until at last they cleave it in 
two. Rifts have been seen by several observers and in 
both caps; and what is most suggestive they always 
appear in the same places, year after year. Sometimes 
oppositions elapse between their several detections 
for they are not the least difficult of detail ; but when 


they arc caught, they prove to lie just where they did 

The permanency in place of the rifts, a characteristic 
true of them all. shows them to be of local habit. Thus 
the rift of 1884 and 1S ( .)7 reappeared again to another 
..I .server in the same position in 1901. They are, there- 
fore features of, or directly dependent on, the surface 
of the planet. But it will not do from this fact to infer 
that they are expressive of depressions there. The 
evidence is conclusive that great irregularities of sur- 
face do not exist on Mars. As we shall see when we 
come to consider the orology of the planet it is certain 
that elevations there of over two or three thousand feet 
in altitude are absent. Differences of temperature, able 
to explain a melting of the ice in one locality coinci- 
dcntally with its retention in an adjacent one, must in 
consequence be unknown. And this much more con- 
clusively than at first appears, for the reason that the 
smaller the planet's mass the less rapidly does its 
blanket of air thin out in ascent above the surface. 
This is in consequence of the greater pull the larger 
Imdy exerts and the greater density it imparts to a com- 
pressible gas like our atmosphere. Gravity acts like 
any force producing pressure and by it the envelope of 
squeezed into a smaller compass. But as this is 
done throughout the atmospheric layer it means a 

ore rapid rarefaction as one leaves the body. The 


action is such that the height necessary to reach an 
analogic density varies inversely as the gravity of the 
mass. In consequence of this, to compass a rela- 
tive thermometric fall for which a moderate difference 
of elevation would suffice on Earth, an immoderate 
one must be made on Mars. For gravity there being 
but three eighths what it is here, eight thirds the rise 
must be made to attain a proportionate lowering of 
temperature. This fact renders the above argument 
against elevation and depression being the cause of 
the phenomenon three times as cogent as it otherwise 
would be. 

With so gradual a gradient in barometric pressure 
there and so low a set of contour lines, altitude must be 
a negligible factor in Martian surface meteorologic 
phenomena. Both density and temperature can be but 
little affected by such cause, and we must search else- 
where for explanation of what surface peculiarities 
we detect. 

Meanwhile the rifts themselves, from being lines 
which penetrate the cap from its periphery in toward 
its centre, end by traversing it in its entirety and sepa- 
rating portions which, becoming outlying subsidiary 
patches, themselves proceed to dwindle and eventually 
disappear. The rifts usually take their rise from such 
broader parts of the cap-encircling blue belt as make 
beads upon that cordon and are clearly spots where the 




product of the melting of the cap is either specially 
collected, or produces its most visible effect. 

So far the description might apply with substantial 
accuracy to cither cap. Yet the conduct of the two is 
in some ways diverse and begins to accentuate itself 
from this point on. 

From the time that the north polar cap reaches a 
diameter of about twenty-five degrees, a singular change 
steals over it. From having been up to then of a well- 
defined outline it now proceeds to grow hazy and 
indistinct all along its edge. This change in its char- 
acter at the same period of its career has been quite 
noticeable at each of the three last oppositions, so that 

small doubt remains that the 
metamorphosis is a regularly 
recurrent one in the history 
of the cap. Coincident with 
the obliteration of its con- 
tour, its dimensions seem- 
ingly enlarge. It is as if a 
hood had been drawn over 
the cap of a dull white dif- 
ferent from the dazzling brilliance of the cap itself 
and covering more ground. Such is probably what 
: with vapor for veil. The excessive melting of 
e ;>}) produces an extensive evaporation which then 
t condenses to be deposited afresh, in part re- 

Northcrn Cap hooded with vapor. 



mains as a covering, shutting off from our view the 
outlines of the cap itself. It would seem that at this 
time the cap melts faster than the air can carry it 
off. A sort of steaming appears to be going on, taking 
place in situ. For it clearly is not wafted away. 
The time of its coming too is significant. For the 
season is May 15, the height of time for a spring haze 
to set in. Then later it dissipates with the same quiet 
indefiniteness with which it gathered. 

It is some time in Martian June before the spring 
haze clears away, and when it does go, only a tiny 
polar cap stands revealed be- 
neath it, from six to eight 
degrees across, or from a 
tenth to a fifteenth of what 
it was when it passed into 
its curious spring chrysalis, 
The date of emergence va- 
ries. In 1903 it occurred 

early, the haze not being Northern Cap unmasked. 

marked after June 3, though recurring again at inter- 
vals for a day or so. In 1905 it was later; percep- 
tibly thin after June 21 it did not certainly clear 
away till June 9 and came back again on July 16 and 
possibly on the 25th. 

These vicissitudes of aspect give us glimpses into a 
sweet unreasonableness in Martian weather which 


makes it seem more akin to our own. And this on two 
counts, diurnal and annual. From day to day at- 
mospheric conditions shift for purely local cause; 
while, furthermore, successive Martian years are not 
alike. In some the season is early; in others late. 
So that Mars is no more exempt than are we from the 
wantonness of weather. 

Clearly disclosed thus reduced to its smallest possible 
terms it remains for some months of our days, for six 
weeks of its own. I hiring that period it continues prac- 
tically unchanged, neither increasing nor decreasing 
significantly in size, nor altering notably in aspect. 
Measures of the drawings of it then make it from five 
i< eight degrees across and it is possible that it really 
fluctuates between narrow limits, though its clear-cut 
outline at all times renders the variation difficult to 
explain. We are not so near it as we could wishj 
for on these occasions even at their best it is over two 
hundred times as distant as the moon and the greatest 
magnification possible still leaves it a hundred thou- 
sand miles away. 

To the south polar cap a somewhat similar history 

ttaches. but with a difference. In its case no such 

regularly recurrent spring haze has yet been noted. 

Iting of this cap would seem to be of a more 

r nature than its fellow and not to outdo what 

can conveniently be carried off. 


That an excess of evaporation should not take place 
is the more peculiar from the fact that at its maximum 
it is the larger of the two and therefore has the greater 
quantity of matter to get rid of. Its summer, also, 
is shorter than the arctic one, so that it has the less 
time to dispose of its accumulations. The only other 
respect in which it seems to be differently circum- 
stanced from its antipodes is in the character of its 
surroundings. About it are large blue-green areas 
which with intermissions stretch down in places to 
within less than ten degrees of the equator; whereas 
the other pole is continuously encircled for long dis- 
tances by practically uninterrupted ochre. The char- 
acter of the environment seems thus the only thing that 
can account for the difference in behavior and this 
proves the more plausible when we come to consider 
what those two classes of regions respectively repre- 

In other ways as well the southern cap is the more 
self-contained. The rifts, indeed, break it up into 
separate portions and these in part remain as outlying 
detachments of the main body, as was notably the 
case in 1877 and in 1894, but they hardly have the 
permanency and importance of those similarly formed 
about the arctic pole. Nothing antarctic for instance 
compares with the subsidiary patch of the north 
polar regions lying in longitude 206, which both 


in Schiaparelli's time, and during the late oppo- 
sitions as well was almost as fixed a feature of the 
arctic zone as the cap proper. Not quite so constant, 
however, and not so solid-looking a landmark is this 
pa tcli for all its extent, which nearly equals the area 
of the more legitimate portion. It bears on its face a 
more pallid complexion as if it were thinner, and this 
is borne out by the fact that it occasionally disappears, 
an event which so far at least has never^ befallen the 
northern cap itself. 

Less constant the southern one is to its own minimum 
than the northern. In some seasons, in most in fact, 
it reaches like the other a more or less definite limit 
of diminution which it does not pass. But this is not 
always the case. In 1894 it disappeared entirely at 
the height of its midsummer. The season was probably 
unusually hoi then in the southern hemisphere of Mars. 

In position the caps have something to say about 
physiographic conditions. Both caps at their minima 
are then irregular and the ('(Mitre of the south one is 
markedly eccentric to the areographic pole. It lies 
some six degrees north along the thirtieth meridian. 
The northern one is also probably eccentric, but much 
so, with :i divergence not much exceeding a degree 
nifl of doubtful orientation. Not only are both caps 
<U H >n their respective poles but they are not oppo- 
^' eaeh other, the one lying in longitude 30, the other 


in 290.) This speaks, of course, for local action. In 
some wise this must depend on the configuration of the 
surface, yet so far as markings go there is nothing to 
show what the dependence is. 

The ec centring of the caps is paralleled by the like 
state of things on earth. The pole of cold does not 
coincide in either hemisphere with the geographic pole. 
On the earth its position is largely determined by the 
distribution of the land-masses. Continents are not 
such equalizers of heat as oceans because of their con- 
ductivity on the one hand and their immobility on the 
other. In winter they part with their heat more quickly 
and convection currents cannot supply the loss. This 
accounting for thermal pole eccentricity is inapplicable 
to Mars because of the absence there of bodies of water. 
And it is significant that the degree the earthly poles 
of cold are out much exceeds what is the case on Mars. 
Possibly areas of vegetation there replace to some effect 
areas of water. It is certainly in favor of this view that 
the arctic regions there are more desert than the ant- 
arctic and that the north pole of cold occupies more 
squarely the geographic pole. 

Not till 1903 did the actual starting again of either 
cap chance to be seen. Nor was this, indeed, a matter 
of hazard but of persistent inquiry by observation 
prolonged after the planet had got so far away that its 
scanning had hitherto been discontinued. Such search 




beyond the customary limits of observation was essen- 
tial to success, because of the relation of the axial tilt 
to the position of the planet in its orbit. At an oppo- 
sition well placed for nearness, the tilt is such as largely 
to hide the pole and to present the polar regions too 
obliquely to view for effective scanning. This is true 
both of the arctic and the antarctic regions in turn. 
For the Martian axis being inclined somewhat as our 
own is to the plane of the planet's orbit, we at times 
sec well and at times but poorly the arctic or antarctic 

The cap, the starting to form of which was thus 
caught, was the arctic one; the date 128 days after 
the northern summer solstice, or thereabouts, for as is 
perhaps natural the advent of the phenomenon partook 
of the wavelike advance 4 of such things familiar on 

earth, an advance succeeded 
by a recession and then fol- 
lowed by another advance. 
So much is proof of local 
weather there as here. Hoar- 
frost was successively de- 
posited and then melted off. 
What is significant, the 
deposition of the frost took 
place simultaneously over large areas. The very first 
patch of it. in about longitude 320, extended at one 

l>r|H>sition <>f frost. 


stroke down to latitude 55. For it actually crossed 
the Pierius somewhat to the south. A second patch 
stretched to the east of the cap. Two wings these made 
to the kernel of cap itself. Through the wings could 
be marked the line of the canal : the Pierius upon the 
one side, the Enipeus upon the other. Such visi- 
bility of the canals through the white stretches proved 
the white not to be due to cloud suspended between us 
and them, but a surface deposit which found no lodg- 
ment upon the canals themselves. The same avoid- 
ance of dark markings was evidenced by the showing 
of the dark rim round the cap's kernel. Now, if the 
deposit were indeed hoarfrost, this failure to find per- 
manent foothold on the dark markings is what we should 
expect to witness. For whether they were vegetation 
or water, equally in either case the frost would melt 
from them first. Probably they were both vegetal, 
though some doubt might exist about the latter, the 
band around the kernel. It was then August 20 in 
that hemisphere. 

Such deposition over great stretches of country is 
perhaps not so surprising as it appears at first sight 
when seen from without in its totality. After all, 
something not unlike it occurs in our snow-storms when 
hundreds of square miles are whitened at once. Fur- 
thermore, with an atmosphere as thin as Mars seems 
to possess the temperature must be perilously near the 



freezing-point in the arctic and subarctic regions at 
the close of summer. 

Steadily, with intermissions, the white sheet increased 
until even the dark border to the cap became obliterate, 
the kernel showing at first through the veil like the 
ghost <>f what it had been, and then ceasing to be visible 
at all, its delimitations being buried under deeper and 
deeper depositions of frost. 

The perennial portion of the cap was thus merged 
in the new-fallen snow. This marked the on-coming of 

the arctic winter in full force 
and happened even before 
the polar sun had wholly set. 
For the pole did not enter 
into the shadow till two of 
our months later, the au- 
tumnal equinox occurring 
183 days after the summer 
solstice or 55 days after the 
first fall of frost. Then the pole passed into its_s tar- 
strewn arctic night, a polar night of twice the duration 
of our own and the circumpolar regions entered upon 
their long hibernation of ten of our months. 

First northern snow. 



FN addition to the polar caps proper and to the 
subsidiary polar patches that often in late sum- 
mer flank them round about, other white spots may 
from time to time be seen upon the disk. In appear- 
ance these differ in no respect, so far as observed, 
from the arctic subsidiary snow-fields. Of the same 
pure argent, they sparkle on occasion in like manner 
with the sheen ofjce. Equally with the polar caps 
they remain permanent in place during the period of 
their visibility and are themselves long-lived. Though 
by no means perpetual their duration is reckoned by 
weeks and even months, and they recur with more or 
less persistency at successive Martian years. That, 
when seen, they show in particular positions apparently 
unaffected by diurnal change precludes their being 
clouds, and this fact taken in connection with the 
character of their habitat is the puzzling point about 
them. For they affect chiefly the north tropic belt. 
They, or at least their nuclei, are small, about two or 
three degrees in diameter, and are not particularly 
easy of detection as a rule, though certain larger ones 


7t MARS AND ITS CANALS chap, vn 

are at times conspicuous. Chromatic, rather than 
formal, definition is necessary to their bringing out, as 
is witnessed by the superb colors the disk presents at 
the times when they are best seen. It is then that 
Mars puts on the look of a fire-opal. 

The first such spot to be noticed was one which 
Schiaparelli detected in 1879, at the second opposition 
in which he studied the planet. He called it the Nix 
Olympica, showing that he recognized in it a cousin- 
ship to the polar snows. Yet it lay in latitude 20 
north, longitude 1 131, in the midst of the ochre 
stretches of that part of the disk. It was a small 
roundish white speck of not more than two thirds the 
diameter of the polar cap. Reseen_by him in 1881, 
it failed to appear at subsequent oppositions and was 
not caught again until 1888. Then once more it van- 
ished, not to be detected anew till many years after 
at Flagstaff, coming out rather surprisingly in 1903. 
It showed, however, in the same place as before; 
so that its position but not its existence is permanent. 

A similar but smaller patch was apparent to Schia- 
parelli at the same opposition of 1879. This one which 

1 Martian longitudes arc now reckoned from the Fastigium Aryn, 

the mythologic cupola of the world, a spot easy of recognition be- 

iking the tongue in the jaws of the Sabaeus Sinus. It further 

- itself because of lying within a degree of the equator. The 

itudes an reckoned thence westward all the way round, or 

to .>.n . 



he styled the Nix Atlantica lay between the Thoth 
and the Syrtis Major. It was about half the size of the 
Nix Olympica and has never since been seen, though 
it should have been had it continued to be what it then 

On the other hand, phenomena of the sort undetected 
of Schiaparelli have been remarked at Flagstaff. On 
May 18, 1901, I was sud- 
denly struck by the singular 
whiteness of the southeast 
corner of Elysium where 
that region bordered the 
Trivium. Elysium has a 
way of being bright but not 
with such startling intensity 
as this spot presented nor 
in so restricted an area as was here the case. The 
spot was so much whiter than anything I had ever 
previously seen outside the polar caps that it arrested 
my attention at once. And this the more that I had 
observed this same part of the planet the day before 
and perceived nothing out of the ordinary. Once 
detected, however, the spot continued visible. The 
next day it was there with equal conspicuousness, and 
now thrust an arm across the Cerberus, entirely ob- 
literating the canal for the space of several degrees. 
In this salience it remained day after day till the 

White in Elysium. 


region passed from sight, to reappear with it six 
weeks later when the region again rounded into view. 
The hour of the Martian day seemed to make no 
difference in its visibility. It was seen from early 
morning till Martian afternoon, as late as the phase 
permitted. Clearly there was nothing diurnal about 
its revealing, and it lasted for at least three months 
and a half, until the planet got so far away that 
observations were discontinued. 

It was to all appearances and intents snow. But 
now comes the singular fact about it. It lay within 
ten degrees of the equator and showed from the end of 
June to the latter part of August. To our ideas there 
could be no more inopportune place or time for such 
an exhibition. For it cannot have been due to a snow- 
rapped peak, as we know for certain that there are no 
mountains in this, or in any other, part of the planet. 
Besides, it had not appeared in previous Martian 
years; which it infallibly would have done had il been 
a peak. Indeed, it baffles explanation beyond any 
Martian phenomenon known to me. It seems directly 
to contradict every other detail presented by the 

The phenomenon is thus unique in kind; it is not, 

however, unique as a specimen of its kind. The eastern 

t of Aeria where that region borders the Syrtis 

Major is prone to a brilliance of the same sort. It is 

chap, vii WHITE SPOTS 77 

a narrow belt of country that shows thus, nothing but 
the coastline itself, but this for a considerable distance 
stretching several hundred miles in length. It has 
stood out saliently bright now at every opposition 
which I have observed, beginning with 1894. Some- 
times it has been described in the notes as bright 
simply, sometimes as white, and once, in 1901, as glis- 
tening at one point like ice. Yet when upon the termi- 
nator it has never stood forth as a mountain range 
should have done to declare its character. 

It has been evident regardless apparently of the Mar- 
tian season. In 1894 it was bright from October 25 
to January 16 (Martian chronology); in 1896, from 
December 22 to January 7 ; in 1901, from July 13 to 
the 15th; in 1903, at about the same date and so in 
1905. It was whitest during the latter oppositions, 
showing that the effect is most marked in its mid- 
summer. All of the above instances of extra-polar 
white have been located within the tropics. Examples 
of the same thing, however, occur in the north tem- 
perate zone. Tempe, a region just to the west of the 
Mare Acidalium, is exceedingly given to showing a 
small white spot close upon the Mare's border in 
latitude 50 north. This spot, too, on occasion 
glitters as it were with ice. It is also at times very 
small. So that whereas much of Tempe is by nature 
bright but a small kernel of it is dazzling. 




Whit.- in tin- Pons Hectoris. 

The list might be easily extended from the record 
book. Thus on March 1 and 2, 1903, the disk showed 
speckled with minute white spots, one in Arcadia in 

latitude 41 north, one in 
Tharsis near the equator, a 
third just north of the 
Phoenix Lucus in 10 south, 
and a fourth, the Nix 
Olympica, and on April 11, 
a flittering pin-point starred 
like a diamond the centre of 
the Pons Hectoris. On both 
these occasions the Martian season was summer; 
July ( .) for the latter, June 21 for the former date. 
\- one approaches the north pole spots of like char- 
acter l>ec<>me more numerous. Especially are such 
visible north of the Mare Acidalium in the arctic region 
thereabout, from 63 to 75 north. 

From so widespread a set of instances the only ex- 
planation which seems to fit the phenomena is that the 
mean temperature of Mars is low, not very much above 
freezing, and that whatever causes a local fall in the 
tempera t ure results in hoar-frost. Such an explanation 
accords well with the distance of the planet from the 
mcl the thinness of its atmosphere. At the same 
shows that the mean temperature over the 
greater part of the planet the greater part of the time 

chap, vii WHITE SPOTS 79 

is above the freezing-point and that consequently 
it is no bar to vegetation of a suitable sort. 

That the hoar-frost should be found even at the 
equator may perhaps be due to the very thinness of 
the air-covering of Mars, which would tend to make 
the actual insolation more of a factor than it is with us, 
and by the great length of the Martian seasons. In 
midsummer the greatest insolation occurs in the arctic 
and temperate, not in the tropic regions ; on the other 
hand, an atmosphere tends to accumulate heat for the 
tropics. With us the latter factor is prepotent; it 
would be less effective on Mars. Then again the double 
duration* of summer would tend to emphasize insolation 
as the important factor in the matter. But it is 
possible that greater deposition plays a part in the 
matter. On earth the rainfall is greatest near the 
equator and something of the sort may be true of the 
zones of moisture on Mars. That the most striking spots 
are found to the west of large dark areas may in this 
connection have a meaning inasmuch as, such regions 
being vegetation-covered, the air over them is probably 
more moisture-laden. 

One point about the position of the spots is of 
moment: they have all been found in the northern 
hemisphere or within ten degrees of it in the southern 
equatorial region. This seems at first a question of 
hemispheres ; but when we consider that the light areas 


of the surface are chiefly in the boreal hemisphere and in 
the south tropic belt, we perceive that it may be rather 
the character of the surface there than the particular 
hemisphere in the abstract that is decisive in the matter. 
Nevertheless, the austral hemisphere is the hemisphere 
of extremes, possessing a shorter, hotter summer and 
a longer, colder winter than its antipodes. This would 
not favor sporadic small depositions of frost in summer 
so much as would a climate of a more mean tempera- 

From the relative lack of atmospheric covering over 
the planet we should expect the nights to prove de- 
cidedly cool, while the days were fairly warm. Of this 
we have perhaps evidence 4 in a singular aspect shown 
by the Mare Acidalium in June, 1903. The account 
of it in the Annals reads thus: "On May 22 an inter- 
esting and curious phenomenon presented itself. On 
that day. so soon as the Mare Acidalium had well 
rounded the terminator on to the disk, at \352, the 
whole of its central part showed white, the edges of 
the marking alone remaining as a shell to this brilliant 
core. So striking was the effect that beside appear- 
ing in the drawing it found echo in the notes. The 
next day no mention is made 4 of it, and a drawing 
made under \20 shows the Mare as usual and the 
bright spot in Tempe in its customary place. Neither 
was anything of the sort noticed on the 24th and 25th. 

chap, vii WHITE SPOTS 81 

But on the 26th, the day of the projection (upon the 
terminator), the effect of the 23d reappeared, the longi- 
tude of the centre being 332. Fortunately on that 
day a further drawing was secured which enabled its 
subsequent behavior to be followed. Made three hours 
later than the other, the longitude of the centre being 
13, this drawing shows the Mare well on the disk, its 
whole area as dark as usual and with Tempe bright to 
the right of it toward the terminator. The terminator 
in question was the sunrise one, and we are offered two 
suppositions in explanation of the phenomenon : either 
the white was due to a morning deposition of hoar-frost 
which dissipated as the sun got up, or obliquity ren- 
dered some superficial deposit visible which more verti- 
cal vision hid. That the former inference is the more 
probable seems hinted at by the simultaneous appear- 
ance from the 19th to the 26th of other areas of white 
between the Mare and the pole. May 26 was 88 days 
after the northern summer solstice, and corresponded 
to July 31 on the earth." Annals, Volume III, 564. 
In this connection mention may pertinently be made 
of Schiaparelli's repeated observation of regions that 
whiten with obliquity, a proclivity to which he par- 
ticularly noticed Hellas and certain 'islands' in the 
Mare Erythraeum to be prone. Here as with the Mare 
Acidalium we certainly seem to be envisaging cases of 
matutinal frost melted by midday under the sun's rays. 



I N gazing at the successive phases presented by the 
polar caps as their annual history unrolls itself to 
view, beginning with vast white cloaks that in winter 
hide so effectively the planet's shoulders, to little round 
knobs that in summer sit like guardsmen's caps more or 
less askew upon the poles, the bodily eye sees only the 
glisten of far-off snow. The mind's eye, however, 
perceives something more: the conviction they carry 
of the presence of an atmosphere surrounding the 
planet. Illusive as water vapor is to sight for its 
transparency and to spectroscopic determination for 
its earthly omnipresence, recognition of its existence 
elsewhere by deduction raises such reasoning at once 
to a more conspicuous plane than it might otherwise 
assume. Especially is this true where the deduction is 
itself conclusive, as is here the case. For it depends 
on phenomena not its own, but which are in their turn 
dependent on it. We are not even beholden to any 
knowledge of the substance composing the caps for the 
fundamental inference that an atmosphere surrounds 
them. Whatever that substance were, the fact that 


chap, viii CLIMATE AND WEATHER 83 

the caps dissipate and reform shows us with absolute 
certainty that they pass into the gaseous state, to be 
later solidified afresh. This gas constitutes of itself 
an atmosphere; while another phenomenon, to wit, 
their blue girdles as they melt, affirming their substance 
to be snow and ice, enables us to precise the fact that 
this gas is water vapor. 

From such premise given us by the polar caps we are 
able to infer much more by the help of the kinetic 
theory of gases. But the speed of parting by a 
planet with its gases is conditioned by the mean 
speed of each gas. Water vapor will, therefore, go 
before nitrogen, oxygen or carbonic acid gas. If, 
then, we find it present over the surface of a planet 
we are assured of the possibility that the other three 
may be there too, and from the similarity of matter 
in space strong reason to suspect that they actually 

Corroborative evidence of the accuracy of the deduc- 
tion as to the presence of a Martian air is shown in 
several other ways ; in the existence of clouds to begin 
with. Rare as they are, these certainly float at times 
over parts of the planet, although it is doubtful whether 
they can then be seen. Fortunately for assurance we 
have other ways of ascertaining their presence than 
that of obscuration. Nor is it of account to the argu- 
ment that they should be few and far between, as they 

8-1 MARS AND ITS CANALS chap, vm 

unquestionably arc One single instance of such medi- 
umistic support is enough to support the theory of a 
medium; and that instance has been more than once 

Direct evidence of atmosphere is further forthcoming 
in the limb-light. This phenomenon might be de- 
scribed as a brilliant obs curat ion. It is a circlet of 
illumination that swamps the features as they near the 
full edge of the disk, the limb of the planet as it is 
called. Obliteration of the sort is evident, more or 
less markedly, at all times, and is not due to foreshort- 
ening, as the broadest areas are affected. The fading 
out of the detail at the limb suggests nothing so much 
as a veil drawn between us and it, lighter in tint than 
what it covers. Such a veil can be none other than 
air or the haze and cloud that air supports. From its 
effect, impartial in place and partial in character, 
cloud is inadmissible as a cause and we are left with air 
charged with dust or vapor in explanation. Obscura- 
tion due to it should prove most dense at the limb, 
since there the eve has to penetrate a greater depth of 
it ; just as on the earth our own air gives azure dimness 
to the distance in deepened tinting as the mountains 
lie remote. 

Another bit of evidence lies in the apparent detec- 
tion <.f a twilight arc. In 1S94 measures made of the 
polar and equatorial diameters of the planet showed 

chap, viii CLIMATE AND WEATHER 85 

certain systematic residuals left after all known correc- 
tions had been applied. The only thing which would 
account for them was the supposition that a twilight 
arc had been unconsciously seen and as unconsciously 
measured. In delicate quantities of the sort too great 
reliance cannot be put, but if the residuals be not refer- 
able to other cause they give us not only further evi- 
dence of an atmosphere, but at the same time our only 
hint of that atmosphere's extent. From them it 
would seem that the air must be rare, not more than 
about four inches of barometric pressure, as we reckon 
it, and probably less; a thin, high air more rarefied 
than prevails upon our highest mountain tops. 

Corroborative of this is the aspect of the planet. 
From the general look of the disk a scant covering 
of air is inferable. For one of the striking things 
about the planet's features is their patent exposure to 
our sight. Except in the winter time of its hemisphere 
or in the spring after the greatest melting of the polar 
cap, nothing seems to stand in our way of an uninter- 
rupted view of the surface, whether in the arctic, tem- 
perate, or tropic zones. From the openness of its 
expression, however, too much case . should not be 
made as we really know but little of how an atmosphere- 
enshrouded planet would look. We find no difficulty 
in seeing objects a hundred miles away across the sur- 
face of the earth and yet the thickness of the air strata 

86 MARS AND ITS CANALS chap, mi 

in such horizontal traversing is many fold what it is 
when we look directly up. It is also out of all propor- 
tion laden with dust and smoke. In the purer regions 
of the earth, a clear air imposes but little bar to sight, 
and conjures up far things startlingly distinct. 

Nevertheless, every evidence points to a thin air 
upon Mars: a priori reasoning, indirect deduction and 
direct sight. Now, from a thinness of atmosphere it 
would follow, other things equal, that the climate was 
cold. About this there has been much question, but 
of answering reply. From the distance of the 
planet from the sun it is certain less heat is received 
by it than falls upon the earth in something like the 
ratio of one to two. But that the amount effective 
is :is the amount received is far from sure. The avail- 
able heat is much affected by the manner of its recep- 
tion. A blanket of air acts like the glass of a conser- 
vatory, letting the light lays in, but hindering the heat 
rays out. The light rays falling on the ground or the 
air are transformed into heat rays that, finding the re- 
turn journey less easy, are consequently trapped. All 
substances are thus calorifiers, but water vapor is 
many times more potent than ordinary air to heat- 
ensnaring. A humid air has a hothouse tang to it most 
perceptible. Now. what the relative percentage of 
water vapor in the Martian atmosphere may be we 
do not know. 

chap, viii CLIMATE AND WEATHER 87 

The thinness of the Martian air has caused it to be 
likened to that upon our highest mountain peaks 
which are in large part covered with perpetual snow. 
But the comparison is not well founded. A peak differs 
materially from a plateau in the countenance it gives 
to the heat falling upon it. On a plateau each warmed 
acre of ground helps the retention of heat by its neigh- 
bor ; while in addition to being destitute of side support 
the higher winds generated about an isolated peak blow 
its own caloric away. Still less does any analogy hold 
between the two when the plateau is a world-wide one. 

From these considerations it is evident glosses are 
possible upon the bald idea of a much lower temperature 
prevailing on the Martian surface than on the earth's. 
Doubtless the theoretic cold has been greatly overdone. 
Reversely, recent observations tend to lower the appa- 
rent temperature disclosed by the features of the disk, 
and between the rising of the theoretic and the falling 
of the observed we are left with a very reasonable 
compromise and reconcilement as the result. 

The various look and behavior of the surface of Mars 
point to a mean temperature colder than that of the 
earth, but above the freezing-point of water; for 
regions, at least, outside of the polar caps and during 
all but the winter months. Except at certain special 
spots, and possibly even there, frost is unknown at all 
times within the tropics and except in winter in tern- 

MARS \M> ITS CANALS chai-. vtn 

perate latitudes. These anomalous localities, men- 
tioned in the preceding chapter, may be said to be the 
exceptions that prove the rule of general non-glacia- 
tion. For if they be snow, they stand witness to its 
absence elsewhere upon the disk, and if they are not, 
they testify the more emphatically to the same effect. 

Vs between different parts of the surface, the tilt 
of the Martian axis and the greater length of the Mar- 
tian seasons, the one the same as, the other the double 
<f. our own, tend to an accentuation of the heat in the 
temperate and arctic or antarctic zones. The greatest 
insolation on earth is not, as we might suppose, at the 
equator, but at the parallels of 43. 5 north and south; 
even the poles themselves receiving a quarter as much 
heat again on midsummer day as ever falls to the lot of 
the line. This broad physical fact is equally true of 
Mars, while in the matter of consecutive exposure Mars 
in summer outdoes the earth. For the longer the sea- 
sons, the more nearly does the effective heat approach 
the received amount. Thus both on the score of heat 
received and of heat husbanded these zones must be 
relatively warm. And this shows itself in the look of 
the surface. In summer it is clearly warmer within 
the polar regions than is the case on earth, to judge by 
the effect. In winter the cold is doubtless propor- 
t innately severe. 

For the diurnal range of temperature we have less 

chap, viii CLIMATE AND WEATHER 89 

data. There is evidence pointing to chilly nights, but 
it is meagre, and we are left to fall back on the cold of 
our deserts at night for analogic condition of the state 
of things over the Martian desert levels after the sun 
goes down. 

If we are uncertain of the precise character of the 
Martian climate, we know on the other hand a good deal 
about<the Martian weather. A pleasing absence of it 
over much of the planet distinguishes Martian conditions 
from our own. That we can scan the surface as we do 
without practical interruption day in and day out 
proves the weather over it to be permanently fair. In 
fact a clear sky, except in winter, and in many places 
even then, is not only the rule, but the rule almost 
without exceptions?) In the early days of Martian 
study cases of obscuration were recorded from time 
to time by observers, in which portions of the disk were 
changed or hidden as if clouds were veiling them from 
view. More modern observations fail to support this 
deduction, partly by absence of instances, partly by 
other explanation of the facts. Certainly the recorded 
instances are very rare. Indeed, occasions of the sort 
must to any Martians be events, since only one possible 
example has presented itself to me during the course 
of my observations, extending more or less over eleven 
years. Even in this case there was no obliteration, 
though a certain whiteness overspread an area near 


the equator temporarily. Position seemed to point to 
its identity with a cloud which made its appearance 
alxmt that time upon the terminator, and lasted for 
some thirty-six hours. The cloud, however, showed 
evidence of being, not the kind with which we are fa- 
miliar, hut a dust-storm, in keeping, indeed, with the 
desert region (Chryse) in which it originated. 

With the exception of sporadic disturbance of the sort 
the whole surface of the planet outside the immediate 
vicinity of the polar caps seems free from cloud or mist 
and to lie perpetually unveiled' to space. In the neigh- 
borhood of the caps, however, and especially round 
about their edge, a very distinct pearly appearance is 
presented during the months at which the cap is at its 
maximum, or in other words, in the depth of its winter. 
( )f a dull white hue and indefinite contour the phenome- 
non suggests cloud/) Where it lies spread no markings 
are visible; an absence explicable by obscuration due 
an interposed medium, but equally well by seasonal 
non-existence of the markings themselves, which from 
the general behavior of these markings we know to be 
to some extent certainly the fact. Of the regions 
where the effect is noticeable, Hellas is the most strik- 
So conspicuously white during the winter of the 
southern hemisphere as to have been often mistaken for 
the polar cap, its ghost shows t hus almost regularly every 
Martian year. What is as suggestive as it is striking, 

chap, viii CLIMATE AND WEATHER 91 

the blanching is confined to the solid circle constituting 
Hellas and does not extend into the dark regions by 
which it is circumscribed. Hellas is as self-contained 
when thus powdered as when, in its normal ochre or 
abnormal red, it stretches like a broad buckler across 
Jhe body of the disk. That the land there lies at a 
higher level than its surroundings is pretty certain, but 
that the difference can amount to enough to explain its 
silveriness as ice is improbable. In latitude Hellas is 
distinctly temperate, lying between the parallels of 55 
and 30 ; but on Mars this is no warrant of a like climate. 
Again, though close on the south to what constitutes 
the polar cap, it does not strictly form part of that cap, 
but occupies both in position and in kind a something 
intermediary between the frost-bound regions of peri- 
odic snow and the warmer ones of perpetual sunshine. 
It seems to be afflicted with the winter weather of the 
north of Europe, and to owe i ts pearly look at such times 
to the same cloud canopy that then distressingly covers 
those inclement lands. 

Similar in behavior to it is the long chain of so- 
called islands that, beginning southwest of Thau- 
masia, runs thence westward even to the eastern edge 
of Hellas. These belt the planet in a west-northwesterly 
direction by a strip of territory from ten to fifteen de- 
grees wide, the medial line of which begins at 55 
south and ends in about 40. They are parted from 

!> MARS AM) ITS CANALS chai-. mi 

the main bright areas by blue-green 'seas' of about the 
same width as themselves, the Mare Sirenum, the Mare 
Cimmerium and. Mare Tyrrhenum. These 'seas' 
the white that covers the 'islands' never crosses; 
though the continent, as we may call it for convenience, 
descends at the east to 30 south. Since the 'seas' 
are nol seas, the cause which might bound the snow, 
were they such, cannot be the cause here. Neverthe- 
hey have an effect of some sort on the isothermal 
lines as is shown not only by latitudinal comparison 
witli the state of things in Hellas, but with that in 
Thaumasia as well. For 30 south is also the limit ap- 
parently of the white on Thaumasia, where ochre desert 
stretches ten degrees farther south still; the region in 
its southern pari being white-mantled, in its northern 
part not. Here again, then, the ochre areas make 
exception to what affects the blue-green ones. Clearly 
the blue-green regions temper the action of what gives 
them wintry cloak. But why they should do this is 
nol easy to explain on any supposition terrestrial or 
marine Bodies of water tend to foster the formation 
of clouds; so, less markedly, do areas of vegetation. 
Neither the old ideas, then, nor the new lend themselves 
in explanation. It may be that while we here seem 
to be envisaging cloud we are in reality looking at hoar- 
frost. ( )n the other hand, light cloud would show less, 
superposed over a dark background, than over an ochre 


one ; and this, the simplest of all explanations, may be 
the true one. It is facts like these that intrigue us in 
the study of the Martian surface by revealing conditions 
which render offhand analogy with the earth unsafe. 
Indeed, we are more sure of some things which appear 
too strange to be true than of others so simple on their 
face as to enlist belief. Among the most difficult 
and perplexing are meteorological problems like the 
above. Here we can only say provisionally that while 
cloud best answers to the appearance, frost best fits the 
cause. For vegetation might melt frost, yet not dissi- 
pate cloud. By raising our conception of the mean 
temperature the facts can, however, be reconciled and 
this is probably the solution of the difficulty after all.) 
As we saw in the annual history of the polar caps a 
dimness somewhat different affects the northern cap in 
May and June. After the melting of the cap is well 
under way a haziness sets in along its edge which be- 
fuddles its outline and effectually hides what is going 
on within it. When at hist the screen clears away the 
cap is found to be reduced to its least dimensions. 
Such obstructing sheet looks to be more of the nature 
of mist caused by the excessive melting of the cap. 
Unfortunately, there are here no patches of blue-green 
to test a possible partiality in its behavior over such 
tracts; nor has similar action ever yet been remarked 
in the case of the cap of the southern hemisphere. 

!l MARS AM) ITS CANALS chap, vm 

i ilar recurrence at the appropriate season of the 
planet's year, together with extensive action at the 
time, takes this springtide mist to some extent out of 
the domain of weather into that of climate. For it 
prevails all round the cap and repeats itself in place 
as each fresh spring comes on. At least it has done so 
for the past three oppositions at which it has been pos- 
sible to observe well the arctic zones. It is thus both 
genera] in its application and fixed in its behavior. 
Nevertheless, it betrays something of the fickleness 
which characterizes that more inconstant thing: 
weather. For it comes and goes, one thinks for good, 
only to find it there again some days later. (^Not less 
captions is the meteoro logic action shown in the mak- 
ing of the new polar cap. When the northern one starts 
to form, vast areas of frost are deposited in a single 
night. These, however, are not permanent. The 
ground thus coyered is during the next few days again 
partially laid bare. Then a new fall occurs, hiding the 
surface a little more completely than before, and the 
lost domain is more than regained. By such wave- 
like advance and recession the tide of frost creeps over 
and submerges the arctic regions as the late summer 
ra into the autumn. In this alternate coming and 
going with succeeding days, we have an unsteadfast- 
ness of action most fittingly paralleled by our own 
weather. It would seem that local causes there as here 

chap, viii CLIMATE AND WEATHER 95 

are superposed upon the orderly progress of the sea- 
sons and though at the on-coming of the autumn the 
cold is steadily gathering strength, nevertheless warm 
days occur now and then to stay its hand, only to be 
succeeded in their turn by frosts more biting than be- 
fore. Even on Mars nothing in the way of weather 
is absolutely predicable but impredicability. ) 



T\ all ways but one our scrutiny of the planet is 
confined to such view as we might get of it from 
the car of a balloon poised above it in space; from 
which disadvantage-point we should see the surface 
only as a map spread out below us, a matter of but 
two dimensions. The exception consists in the obser- 
vation of what are called projections; irregularities 
visible when the disk is gibbous upon that edge of the 
planet where the light fades off. Striking phenomena 
in themselves they are of particular value for what may 
be deduced from them. For by them we are afforded 
our only opportunity of gaining knowledge of the sur- 
face other than in plan and thus of determining be- 
tween peak, plateau, or plain that to a bird's-eye view 
alike lie flattened out to one dead level. 

It might at first be thought that our best chance of 
noting any elevations or depressions of the Martian 
surface lay in catching that surface in profile, by scan- 
ning the bright edge of it which stands sharp-cut 
against the sky and is called the limb. For this is 
practically what we do on earth when we mark a 



mountain against the horizon and measure its height 
by triangulation. Unfortunately the method fails in 
the case of Mars because of the great distance we are 
away. Unless the planet were distinctly more gen- 
erously equipped than the earth in the matter of 
mountains, nothing could be hoped from so forthright 
an envisaging. So relatively insignificant to the size 
of its globe is the relief of the earth's surface that an 
orange skin would seem grossly rough by comparison. 
The same proves true for Mars. With the greatest 
magnification we can produce, the Martian limb still 
appears perfectly smooth. 

Luckily, while direct vision is thus impossible, oblique 
illumination enables us to get an insight into the 
character of the surface we had otherwise been 
denied. When mountains or valleys chance to lie 
upon the boundary of light and darkness, the rim of 
the disk known as the terminator in contradistinction 
to the limb where the surface itself comes to an end, 
they make their presence evident through an indirect 
species of magnification, the elongate effect of oblique 
lighting. With a practical instance of it every one 
is familiar who has walked by night along a road im- 
perfectly starred at intervals by electric lights. Startled 
between posts by what seemed deep holes and high 
furrows he has involuntarily imitated a spavined horse 
for fear of stubbing his toes, only to encounter when 


his foot fell a surface on contact surprisingly smooth. 
The slant illumination by lengthening the shadows 
had painfully deceived him into exaggerated inference 
of irregularity. What proves disturbing to a way- 
farer misguided by arc lights is made to do the 
eve sci- vice when it comes to planetary interpreta- 
tion. On the boundary of light and shade, those 
parts of the surface where it is sunrise or sunset 
upon the planet, the sun's rays fall so athwart wise 
as to throw enormous shadows from quite small eleva- 
tions to an eye so placed as to view the surface with 
anything approaching perpendicularity. A mountain 
mass there will thus proclaim itself by protracted pro- 
file upon the plain in hundredfold magnification. Simi- 
larly a peak there will advertise its height by catching 
the coming or holding the lingering light jit many times 
the distance of its own elevation away from the night 
side of the planet. Here, if anywhere, then, could 
mountains be expected to disclose themselves, and 
here, when existent, they have as a matter of fact 
been found. 

< mr own moon offers us the first and easiest example 
of such vicariously visible relief. When the moon is 
near the quarter, and for three or four days on either 
side of that, a keen eye can usually detect one or more 
knobs, like warts, projecting from its terminator, 
easily distinguished from the limb both by reason of 


being less bright and of being bounded by a semi-ellipse 
instead of a semicircle. If a telescope or even an opera- 
glass be substituted for the eye, it is possible to see 
what causes them; the knob resolves itself into the 
illuminated rim of a crater separated from the main 
body of the visible moon by the seemingly black void of 
space. The peak has caught the sunlight, while its 
foot and the country between it and the illuminated 
surface still lies shrouded in shadow. 

From measurement of the distance the sun-tipped 
peak seems to stand aloof from the line where the plain 
itself is touched by the light, the height of it above that 
plain may be calculated. In this way have been found 
the heights of the mountains of the moon. Incidentally, 
brain outstrips brawn. For pinnacles no Lunarian 
could scale, both for their precipitous inaccessibility 
and their loftiness, man has measured without so 
much as setting foot upon their globe. At each lunar 
sunrise and again at lunar sunset these old crater walls 
show their crescent coronets tipped the reverse way; 
and peaks higher than the Himalayas make gigantic 
gnomons of themselves with hands outstretched to grasp 
the plains. 

In this manner a lunar peak of fifteen thousand feet 
shows its presence to the unaided eye. With so much 
for starting-point we can calculate how low an eleva- 
tion could similarly be made out on Mars under a like 

100 MARS AND ITS CANALS chap, n 

phase illumination. Now, in spheres of different diame- 
ters the distance out from the terminator for a given 
height is as the square root of the diameter. Mars has 
about twice the size of the Moon. In consequence, if 
we saw the planet at the same distance off as the Moon, 
the height of a peak upon it sufficient to cast an equal 
shadow or be seen at an equal separation from the- 
terminator need he but two thirds as high. To see 
it thus equidistant a power of 250 or 300 is necessary, 
dependent on the opposition. Twice this power may 
at times be used, and by the same reasoning this 
would reduce the height sufficient to show by four 
or to something like 2500 feet. This, then, would be 
the theoretic limit of the visible, a limit needing to 
be somewhat increased because of the imperfection of 
our air. 

Having found thus what should be visible on Mars 
we turn now to see what is. At once we find ourselves 
confronted with a very unlunar state of things. Com- 
mon upon the face of the Moon, excrescences of the 
terminator are rare on Mais. The first ever seen was 
detected by a visitor at the Lick Observatory in 1888. 
Since then they have Keen repeatedly noticed both at 
the Lick and elsewhere. But although observers are 
now on the watch for them, they are not very fre- 
quently chronicled because not of everyday occurrence. 
Much depends upon the opposition; some approaches 


of the planet proving more prolific of them than others. 
How rare they are, however, may be gathered from the 
fact that the last three oppositions have disclosed but 
one apiece. 

An account of the great projection of May 25, 1903, 
will give an idea of the extent and interest of the phe- 
nomenon and will serve to show to what cause we must 
attribute all such that have been visible on Mars, for 
the behavior of this one was typical of the class. 

About half past eight o'clock in the evening of May 
26, 1903, Mr. V. M. Slipher, astronomer at Flagstaff, 
shortly after taking over the telescope then directed 
upon Mars, suddenly noticed a large projection about 
halfway up the terminator 
of the planet. He at once 
sent word of the fact and 
the observatory staff turned 
out to see it, for a projec- 
tion has for workers on Mars 
the like interest that a new 
comet possesses for astrono- 
mers generally. In this case 
the phenomenon was specially potent in that it was 
the first to be detected that year. Its singularity was 
amply seconded by its size. For it was very large, its 
extent both in length and height being excessive. 
When I first saw it, the projection consisted of an 

102 MARS AND ITS CANALS chap, ix 

oval patch of light, a little to the north of the centre 
of the phase ellipse lying parallel to the terminator 
but parted from it by darkness to the extent of half 
the projection's own width. It made thus not simply 
an excrescence but a detached islet of light. It was 
easily seen by all those present and was carefully 
studied from that time on by Mr. Slipher and me. 
Both of us made drawings of it alternately at inter- 
vals, as well as micrometer measures of its position. 
Next to its great size, the most striking feature about 
it was its color. This, instead of being white or whitish, 
ochre orange, a hue closely assimilated to the tint 
of the subjacent parts of the disk, which was the region 
known as Chryse. This distinctive complexion it kept 
throughout the period of its apparition. At the same 
time Baltia, a region to the north of it and synchro- 
nously visible close upon the terminator, showed whitish. 
The seeing was good enough to disclose the Phison and 
Euphrates double, the power a magnification of 310 
and the aperture the full aperture of the 24-inch 


From the time it was first seen the detached patch 
of light crept in toward the disk, the illuminated body 
of the planet. Four minutes after I noted it the dark 
space separating it from the nearest point of the termi- 
nator had sensibly lessened. So it continued, with 
some fluctuations intrinsic to the atmospheric diffi- 


culties of observations generally and to the smallness 
of the object itself, to become gradually less and less 
salient. It lasted for about forty minutes from the 
moment it had first appeared to Mr. Slipher and then 
passed from sight to leave the edge of the planet smooth 
and commonplace again. 

The measures made on it showed that it lay when 
first seen in longitude 39.7, latitude 18.5 north, and 
that its highest point stood seventeen miles above the 
surface of the planet. It was three hundred miles 
long. These are my own figures, from which Mr. 
Slipher's do not substantially differ. 

The return of the part of the planet where it had been 
seen was eagerly awaited the night after by both 
observers, to see if it would bring the projection with it. 
For only once a day is the same region of Mars similarly 
presented. But in order not to miss the projection, 
should it be ahead of time, observations were begun 
before it was due. Shortly after they were started, 
there appeared higher up the terminator and therefore 
farther north than had been the case the night before, 
a small projection. It was with difficulty made out 
and its position measured. Without careful watching 
it must have been missed altogether. As it was, it 
differed in every respect from that of the preceding 
day. It was not nearly so high, not nearly so large, 
and lay in a different place on the planet, being now 

104 MARS AND ITS CANALS chap, ix 

in longitude M.~, latitude 25.5. Either the two, 
therefore, were totally different things or the projec- 
tion had moved in the elapsed interval of time over 
seven degrees of latitude and eight degrees of longitude, 
a distance of three hundred and ninety miles in twenty- 
four hours. Where the previous projection had been 
nothing showed. On the following night, May 28, no 
trace of anything unusual could be seen anywhere. 

We are now concerned to inquire to what this series 
of appearances could have been due. The first observ- 
i projections on Mars had unhesitatingly attrib- 
uted them to the same cause that produces projections 
on the Moon, to wit, mountains. Such they were 
held to be in France and at the Lick. This view, how- 
ever, was in L892 disputed by W. H. Pickering who 
considered them to be not mountains, but cloud. And 
this view was strongly supported by A. E. Douglass 
in a discussion of a large number of them observed in 
1894 at Flagstaff. The mountain theory of their 
generation was finally shown to be untenable and their 
ascription to cloud conclusively proved to be the cor- 
rect solution by the observations of a remarkable 
one made in December, 1900, and the careful 
study to which by the writer they were subjected. 
\\r shall now explain how this was done and we will 
liegin by pointing out that the fact that only a single 
specimen of the phenomenon was visible at each of the 


three oppositions of 1900, 1903, and 1905 was itself 
conclusive, rightly viewed, of their non-mountainous 
character. This conclusion follows at once from the 
isolateness of the phenomenon. For a mountain cannot 
change its place. Now, the shift in the aspect presented 
by the planet's disk from one night to the next is not 
sufficient to alter perceptibly the appearance shown 
by anything upon its edge on the two occasions. If, 
then, a peak stood out upon it one evening, the peak 
should again show salient when the region reached the 
same position upon the succeeding night. That noth- 
ing then was seen where something had previously 
been visible proved the phenomenon not that of a 
mountain peak, since what produced the projection 
was clearly not fixed in place and therefore not attached 
to the soil. Now the only other thing capable of catch- 
ing the light before it reached the surface would be 
something suspended in the air, that is, a cloud. De- 
duction, therefore, from the rarity of the phenomenon 
alone showed that the projections must be clouds. 

Their behavior in detail entirely corroborates this 
deduction from their intermittence. Such was shown 
by the action of the projection of December 6, 1900, 
as set forth in a paper before the American Philosophi- 
cal Society and such again by that of the one of May 
26, 1903, as we shall now note. To begin with, we 
notice that the projection seen on May 26 was not 

100 MARS AM) ITS CANALS chap, rt 

found either in situ or in size on May 27 and had wholly 
vanished on May 28, though the seeing was substan- 
tially the same if not better on the two nights succeed- 
ing that of its original detection. Hence in its own 
instance this projection proved an alibi irreconcilable 
with the character of a mountain mass. But it did 
more. It not only was not on the second evening 
what and where it had been on the first, but the remains 
of it visible on the second occasion showed clearly that 
it had moved in the meantime . Furthermore it was 
disappearing as it went, for it was very much smaller 
after the lapse of twenty-four hours. JThe s omething 
that caused it was not only not attached to the soil, 
but was moving and dissipating as it moved. Only 
one class of bodies known to us can account for these 
metamorphoses and that is: cloud. 

But what kind of cloud are we to concei ve it to be? 
< >ur ordinary vapor clouds are whitish and this would 
be still more their color could they be looked at from 
alx)ve. The Martian cloud was not white but tawny, 
of the tint exhibited by a cloud of dust. Nor could 
this color have very well been lent it by its sunrise 
position, for other places equally situated to be tinged 
by the hues of that time of day, Baltia to wit, showed 
distinctly white. So that we must suppose it to be 
what it looked, a something of the soil, not beholden 
to atmospheric tinting for its hue; a vast dust-cloud 


traveling slowly over the desert and settling slowly 
again to the ground. 

Precisely the same general course of drifting disap- 
pearance was taken by the projection of December 7 
and 8, 1900. And this, too, stood an unique appari- 
tion in the annals of its opposition. Clouds, then, and 
not mountains are the explanation of the projections 
on Mars, differing thus completely from the lunar ones. 



[ \ESCENDING now equatorwards from the polar 
-*-^ regions, and their in part paleocrystic, in part 
periodic, coating of ice, we come out upon the general 
uncovered expanse of the planet which in winter com- 
prises relatively less surface than on Earth, but in sum- 
mer relatively more. Forty degrees and eighty-six 
degrees may be taken as the mean hiemal and sestival 
limits respectively of the snow on Mars; forty-five 
and seventy-five as those of the Earth. Whatever 
ground is thus bared of superficial covering on Mars lies 
fully exposed to view, thanks to the absence of obscur- 
ing cloud; and it is at once evident that the terrrane 
is diversified, patches of blue-green alternating with 
stretches of reddish ochre. Of the two opaline tints 
the reddish ochre predominates, fully five eighths of the 
disk being occupied by it. 

It was early evident in the study of the surface 
of Mars that its ochreish disk was not spotless. 
Iluyghcns in L659 saw the Syrtis Major. From this 
first fruit of areography dates, indeed, the initial recog- 
nition of the planet's rotation; for on noting that 



the marking changed its place, he inferred a turning of 
the planet upon itself in about twenty-four hours. Thir- 
teen years later he observed and drew it again and this 
time in company with the polar cap. Again, after 
eleven more years, he depicted it for the third time, and 
now so changed because of the different tilt of the planet 
toward the earth that it may be doubted whether Huy- 
ghens himself recognized it for the same. But that 
he drew it correctly a globe of Mars will at once show. 
From such small beginning did areography progress 
to the perception of permanent patches of a sombre hue 
distributed more or less irregularly over the disk. Im- 
pressing the observers simply as dark at first, they later 
came to be recognized as possessing color, a blue-green, 
which contrasted beautifully with the reddish ochre 
of the rest of the surface. Cassini, Maraldi, Bianchini, 
Herschel, Schroeter, all saw markings which they re- 
produced. Finally, with Beer and Maedler, came the 
first attempt at a complete geography. In and out 
through the ochre was traced the blue; commonly in 
long Mediterraneans of shade, but here and there in 
isolated Caspians of color. With our modern tele- 
scopic means the dark patches are easily visible, the 
very smallest glass sufficing to disclose them. When 
thus shown they much resemble in contour the dark 
patches on the face of the Moon as seen with the naked 
eye. Now these patches were early taken for lunar 

110 MARS AND ITS CANALS chap, x 

seas and received names in keeping with the conception; 
as the Sea of Serenity, the Sea of Vapors, and so forth. 
Following the recognition of a like appearance, like 
appellatives were given to the Martian markings; and 
the Mare Sirenum, or Sea of the Sirens, the Mare Cini- 
merium, and others sufficiently proclaim what was 
thought of them at the time they were thus baptized. 
Indeed, if a general similarity be any warrant for a 
generic name they were not at the time ill-termed. 
For, conn non to all three bodies, the Earth, the Moon, 
and the planet Mars, is the figuration of their surfaces 
into light areas and dark. In the Martian disk, as in 
the lunar one, we seem to be looking at a cartographic 
presentation of some strange geography suspended in 
the sky; the first generic difference between the two 
being t hat t he chart is done in chiaroscuro for the Moon, 
in color for Mais. On mundane maps, we know the 
dusky washes for oceans; so on the Moon it was only 
natural to consider their counterparts as maria; and 
nil Mars as 'seas.' Nor did the blue-green hue of the 
Martian ones detract from the resemblance. 

Hut in something other than color these markings are 
alike. In fact, color could hardly be excuse for consider- 
ing the lunar maria what their name implies, for dis- 
tinctive tint is lacking in them, even to the naked eye. 
It in form that the likeness lay. Their figures 
>uch as our own oceans show; and allowing for 


a sisterly contrast amid a sisterly resemblance, the 
lunar maria or the Martian seas might well have been 
of similar origin to those with which our schoolboy 
study of atlases had made us familiar. Thus did simi- 
larity in look suggest similarity in origin, and intuitive 
recognition clothe its objects with the same specific 

Considerable assumption, however, underlay the 
pleasing simplicity of the correlation on other grounds, 
consequent not so much upon any lack of astronomic 
knowledge as, curiously, upon a dearth of knowledge of 
ourselves. We know how other bodies look to us, but we 
ignore how we look to them. It is not so easy to see 
ourselves as others see us ; for a far view may differ from 
a near one, and a matter of inclination greatly alter 
the result. Owing both to distance and to tilt we 
lack that practical acquaintance with the aspect of our 
own oceans viewed from above, necessary to definite 
predication of their appearance across interplanetary 
space. Our usual idea is that seas show dark, but it is 
also quite evident that under some circumstances they 
appear the contrary. It all depends upon the position 
of the observer and upon the position of the Sun. Their 
usual ultramarine may become even as molten brass 
from indirect reflection; while on direct mirroring, 
they give back the Sun with such scarce perceptible 
purloining of splendor as to present a dazzling sheen 

lli MARS AND ITS CANALS chap, x 

not t<> be gazed upon without regret. Canopied by a 
welkin they assume its leaden hue, while at the same 
time, their shores, less impressionable to borrowed light- 
ing, show several tints darker than themselves. Sur- 
faces so sensitive to illumination hardly admit of more 
accusable tint than a chameleon. Nevertheless, we are 
probably justified in our conviction that perpendicularly 
visaged, they would on the whole outdo in sombreness 
land round about them, and so be evident as dusky 
patches against a brighter ground. 

( )ne phenomenon we might with some confidence look 
to see exhibited by them were they oceans, and that is 
the reflected image of the Sun visible as a burnished 
glare at a calculable point. Specular reflection of the 
sort was early suggested in the case of Mars, and physical 
ephemerides for the planet registered for many years 
the precise spot where the starlike image should be 
sought. Hut it was never seen. Yet not till the marine 
character of the Martian seas had been otherwise dis- 
proved was the futile quest for it abandoned. Indeed, 
it was a tacit recognition that our knowledge had ad- 
vanced when this column in the ephemeris was allowed 
t<> lapse. 

On this general marine ascription doubt was first 

in the case of the Moon. So soon as the telescope 

came to he pointed at our satellite, it was evident that 

e darker washes were not water surfaces at all, but 


very palpably plains. Long low ridges of elevation 
stood out upon them like prairie swells, which grew in 
visible relief according to the slanting character of the 
illumination. Cracks or rills, too, appeared near their 
edges and craters showed in their very midst. Pat- 
ently solid they betrayed their constitution not only 
by diverse topography but by diversified tint. All 
manner of shades of neutral tone mottled their surface, 
from seeming porphyry to chalk. Belief perforce de- 
parted when the telescope thus pricked the bubble, 
evaporating as the water itself had done long before. 

So much was known before the Mars' markings were 
named. Nevertheless, humanity, true to its instincts, 
promptly proceeded to commit again the same mistake, 
and, cheerfully undeterred by the exposure of its errors 
in the case of the Moon, repeated the christening in the 
case of Mars. So sure was it of its ground that what 
it saw was not ground, that though the particular ap- 
pellatives of the several seas were constantly altered, 
rebaptisms, while changing the personal, kept the generic 
name. Dawes' Ocean, for example, later became 
l'Ocean Newton and later still the Mare Erythraeum, 
but remained set down as much a sea as before. About 
thirteen years ago, however, what had befallen the 
seas of the Moon, befell those of Mars: the loss of 
their character. It was first recognized through a 
similar exposure ; but the fact was led up to and might 

114 MARS AM) ITS CANALS chap, x 

have been realized in consequence of quite a different 
line of evidence. The initial thing to cast doubt upon 
the seas being what they seemed to be was the detection 
of change in their aspect. That the detection was not 
made much earlier than actually happened shows how 
a phenomenon may elude observation if scrutiny be 
not persistent, and its results from time to time not 
carefully compared. Schiaparelli was the one who 
first noticed variation in the look of the seas, and the 
discovery was as much due to the assiduity with which 
he followed the planet opposition after opposition as to 
the keenness with which he scanned it. The noting of 
change in the blue-green areas constituted, in fact, one 
of the first fruits of systematic study of the planet. 
Change in configuration, that is, alteration of area, pre- 
ceded in recognition alteration of tint. Thus the 
Syrtis Major showed larger to him in 1879 than it had 
in 1^77. This was natural ; difference of degree being 
:i more delicate matter to perceive than its effect upon 
extent. From change of area his perception went on 
to change of tone. In his own words, what he noticed 
was this: Memoria, VI, 1888, "No less certain is it 
that, from one opposition to another, one notices in the 
. very remarkable alterations of tone. Thus the 
regions called Man* Cimmerium, Mare Sirenum, and 
Solis Lieus, which during the years 1877 to 1879 could 
be numbered among the most sombre on the planet, 


during the succeeding oppositions became less and less 
black, and in 1888 were of a light gray hardly sufficient 
to render them visible in the oblique position in which 
all three found themselves. ... On the other hand, 
at the very same moment, the Mare Acidalium and the 
Lacus Hyperboreus showed very dark; the latter in- 
deed appeared nearly black, although seen as tilted as 
the Syrtis and the equatorial bays. The condition of the 
regions called seas is therefore not constant : so much 
is unquestionable. Perhaps the change produced in 
them has to do with the season of the planet's year." 

Holding as he did the then prevailing view that the 
blue-green regions were bodies of water, he regarded 
those of intermediate tint as vast marshes or swamps, 
and he accounted for change of hue in them as due to 
inundations and occasions of drying up. In conse- 
quence of losing their water, the seas, he thought, 
had in places become so shallow that the bottom 
showed through. 

Plausible on the surface, this theory breaks down so 
soon as it is subjected to quantitative criticism. For 
the moment we try to track the water, we detect the 
inadequacy of the clew. The enormous areas over 
which the phenomenon occurs necessitates the estab- 
lishing an alibi for all the lost water that has gone. 
Drying up on such a scale would mean the removal 
of many feet of liquid over hundreds of thousands of 

lit; MARS AND ITS CANALS chap, a 

miles in extent. To produce any such change in ap- 
pearance as we witness, even on the supposition that 
these seas were none too deep to start with, would in- 
volve lowering the level of the water by from five to 
twenty feet throughout two thirds of the whole sur- 
face of the southern hemisphere. This would leave a 
heap of waters to he accounted for, bewildering in its 
immensity. The myriad tons of it must be disposed of; 
either by drainage 4 into other regions or by being caught 
up into the sky. 

In this emergency it might seem at first as if the polar 
cap of t he opposite hemisphere offered itself as a possible 
reservoir for the momentarily superfluous fluid. But 
such hoped-for outlet to the problem is at once closed 
by the simple fact that when the lightening of the dark 
regions of the southern hemisphere takes place, the 
opposite polar cap has already attained its maximum; 
in fact, has already begun to melt. It, therefore, abso- 
lutely refuses to lend itself to any such service. This 
was not known to Schiaparelli's time, the observations 
which have established it, by recording more completely 
the history of the cap, having since been made. In- 
dml, it was not known even at the time when the writer, 
in 1894, showed the impossibility of the transfer on other 
grounds; to wit. on the fact of no commensurate con- 
it .nit darkening of the surface elsewhere and on the 
manifest non-complicity, if not impotency, of the Mar- 


tian atmosphere in the process. The trai S;>re\'ee of 
the water to other dark patches in the northern hemi- 
sphere fails of sufficiency of explanation because of 
the limited extent of such areas on that side of the 
globe; while the air is quite as incapable of carrying 
away any such body of liquid, though the whole of it 
were at the saturation-point, not to mention that there 
exists no sign of the attempt. The reader will find 
this reasoning set forth in Mars, published eleven 
years ago. He will now note, from what has been said 
above about the northern polar cap, that continued 
observations since have resulted in opening up another 
line of proof which has only strengthened the conclusion 
there reached. 

The coup de grdce, however, to the old belief was 
given when the surface of the dark areas was found 
to be traversed by perma- ^^^^^^ 

nent lines by Pickering 
and Douglass. Continued 
observation showed these 
lines to be unchangeable in \ 
place. Now permanent \ 
lines cannot exist on bodies 
of water,, and in conse- 
quence the idea that what lines in dark area. 
we looked on there were water surfaces had to be 

118 MARS AND ITS CANALS chap, x 

Thus we now know that the markings on both the 
Moon and Mars which have been called maria are not 
in reality seas. Yet we shall do well still to keep the 
old-fashioned sonorous names, Mare Erythraeum, Mare 
Sirenum, and their fellows, because it is inconvenient 
t<> change; while, if we please, we may see in their con- 
secrated Latin couching the fit embalming in a dead 
language of a conception that itself is dead. 



OINCE closer acquaintance takes from the maria 
their character of seas, we are led to inquire again 
into their constitution. Now, when we set ourselves 
to consider to what such appearances could be due we 
note something besides sea, which forms a large part 
of our earth's surface, and would have very much 
what we suppose the latter's aspect from afar to 
be, not only in tone, but in tint. This something is 
vegetation. Seen from a height and mellowed by 
atmospheric distance, great forests lose their green to 
become themselves ultramarine. 

To dispossess a previous conception is difficult, but 
so soon as we have put the idea of seas out of our heads 
(k vegetal explanation proves to satisfy the phenomena, 
even at first glance, better than water surfaces. In 
their color, blue-green, the dark areas exactly typify 
the distant look of our own forests; whereas we are 
not at all sure that seas would. From color alone we 
are more justified in deeming them vegetal than marine) 
But the moment we go farther into the matter the 
more certain we become of being upon the right road. 



With increased detection the markings they reveal and 
the metamorphoses they undergo, while pointing away 
from water, point as directly to vegetation) All the 
inexplicabilities which the supposition of water in- 
volves find instant solution on the theory of vegetal 
growth. The non-balancing of the areas of shading 
in their shift from one part of the disk to another, no 
longer becomes a circumstance impossible to explain, 
but a necessary consequence of their new-found char- 
acter, denoting the time necessary for vegetation to 
sprout. The change of hue of vast areas from blue- 
green to ochre no longer presupposes the bodily trans- 
ference of thousands of tons of substance, but the quiet 
turning of the leaf under autumnal frostsj Even the 
fact that they occupy those regions most fitted by figure 
to contain oceans fits in with the same conception. 
For that the Martian equivalents of forest and moor- 
land, tree and grass, should grow now in the lowest 
parts of the planet's surface is what might not unrea- 
sonably be expected from the very fact of their being 
low. since what remained of the water would tend 
both "ii the surface and in the air to drain into them. 
For the change in question to be vegetal it must occur 
at t he proper season of the planet 's year. This we must 
now consider. We have said that Schiaparelli de- 
tected change in the blue-green regions and suspected 
this change of seasonal affiliation, lie inferred this 


chap, xi VEGETATION 121 

from piecing together the aspects of different seasons 
of different years as shown in consecutive Martian oppo- 
sitions. To mark it actually take place in a single Mar- 
tian year came later. In 1894, at Flagstaff, the south- 
ern hemisphere was presented during its late spring 
and early summer ; it was observed, too, for many of 
our months in succession. During this time the planet 
was specially well circumstanced for study of the 
change in that hemisphere, both by reason of the ap- 
positeness of the season and of the unusual size of the 
disk. Advantage was taken of the double event to 
a recording of the consecutive appearances certain 
regions underwent, and the contrasted states thus ex- 
hibited were such as clearly to betoken the action of 
seasonal change. What Schiaparelli had thus ably 
inferred from diverse portions of different Martian 
years was in this case shown occurring in one and the 
same semestral cycle. 

Usually the change of hue seems essentially one of 
tone; the blue-green fades out, getting less and less 
pronounced, until in extreme cases only ochre is left 
behind. It acts as if the darker color were superim- 
posed upon the lighter and could be to a greater or less 
extent removed. This is what Schiaparelli noted and 
what was seen in 1894 at Flagstaff. Three views en 
suite of the chain of changes then observed are shown 
in Mars, the region known as Hesperia being central 

122 MARS AM) ITS CANALS cbaf. a 

in each. Comparison of the three discloses a remark- 
able metamorphosis in that "promontory," a rise into 
visibility by a paling of its complexion. Nor is the 
contrast confined to it; changes as salient will be 
noticed in the pictures over the other parts of the disk. 

There have been instances, however, of a metamor- 
phosis so much more strange as to deserve exposition 
in detail; one where not tone simply is involved, but 
where a quite new tint has surprisingly appeared. 

On April 19, 1903, when, after being hidden for 
t hirt y < lays, < >wing to the different rotation periods of the 
two planets, the Mare Erythraeum, the largest blue- 
green region of the disk and lying in the southern hemi- 
sphere, rounded again into view, a startling transforma- 
tion stood revealed in it. Instead of showing blue- 
green as usual, and as it had done six weeks before, it 
was now of a distinct chocolate-brown. It had been 
well seen at its previous presentation, so that no doubt 
existed of its then tint. At that time the Martian sea- 
son corresponded to December 30 in our calendar. 
Eighteen Martian days had since elapsed, and it was 
now January 10 there. The metamorphosis had taken 
place, therefore, shortly after the winter solstice of that 
pari of the planet. The color change that had super- 
vencd proved permanent. For the next night the 
region showed the same brown hue, and so it contin- 
ued to appear throughout the days that it was visible. 





Two months passed, and then the chocolate hue had 
vanished, gone as it had come, and the mare 
had resumed its usual tint, except for being some- 
what pale at the south. It had come to be Febru- 
ary 21 on Mars. Timed and tabulated, the meta- 
morphosis through which the mare passed stands 
out thus : 

Mare Erythraeum 1903 

Days before or 


after Summer 

(Before = 

After = +) 



February 16 


December 16 


March 20 

+ 22 

January 1 


April 19 


January 16 


April 22 


January 18 


May 26 


February 4 

Faint chocolate 

May 30 


February 6 

Faint chocolate 

June 30 


February 22 

Faint blue-green 

July 7 


February 25 

Faint blue-green 

The culmination of the transformation seems to have 
taken place about 60 days after the southern winter 
solstice, or in the depth of the Martian winter of that 
hemisphere. This is certainly just the time at which 
vegetation should be at its deadest. 

The northern and southern portions of the mare did 
not behave alike in taking on the chocolate tint. 
From the notes made about them during the opposition 
it appears that the latter was later than the former in 




undergoing the metamorphosis, as will be seen from 
the following depth of the blue green estimated in 
percentages shown at different dates, calling the deepest 
tone ever exhibited by it unity. 

ii arti an 







.1 KM AR1 
















From this table we may place the lowest point of the 
blue-green tint as reached about the 22d of Janu- 
ary for the northern, the 5th of February for the 
southern, part. This would indicate that the wave 
of returning growth came from the north, not the south ; 
an important fact, as we shall see later in studying the 
action of the canals. 

At the next opposition, in 1905, a recurrence of the 
transformation was watched for, and not in vain. It 
occurred, however, somewhat later in the Mart'ian sea- 
son. On December 27 of the pla net's current year the 
Mare Erythraeum was still as usual, blue-green, nothing 
out of the ordinary being remarked in it; and so it was 
on its. January 17, although the southern edge was darker 
than the northern. It looked certainly as if the meta- 
morphosis were this year to be omitted. But such 
was imt the case. When the region again came round, 
on February 1 of the Martian calendar, there the strange 




tint was as unmistakable as it had been on its original 
occurrence. Not only was the Mare Erythraeum so 
colored, but on February 5 (Martian) the northern por- 
tion of the Mare Cimmerium was observed to be simi- 
larly affected. In the Mare Erythraeum the anomalous 
chocolate hue was confined to a belt between the lati- 
tudes of 10 and 20 south of the equator ; in the Mare 
Cimmerium it stretched a little higher, from 10 at the 
west to 25 at the east. It is noteworthy that the 
southern portion of the latter showed blue at the time 
the northern showed brown. Then the metamor- 
phosis proceeded as shown in the following table: 

Mare Erythraeum 1905 


Days after Winter 

Solstice of Southern 




January 25 


December 27 


March 6 


January 16 


April 4 


January 31 


April 12 


February 4 


April 30 


February 13 

Faint chocolate 

May 8 


February 17- 

Faint chocolate 

May 12 


February 19 

Faint blue-green 

June 11 


March 6 

Faint blue-green 

June 15 


March 8 

Faint blue-green 

July 16 


March 23 

Pale bluish green 

Here, as in 1903, a chromatic rise and fall is evident ; 
the culmination of the change occurring in Martian early 
February about ninety days after the winter solstice. 
That it was not of long duration is also indicated. If 



we examine the evidence for the two portions of the 
mare separately, the northern and the southern, as in 
1903, we find it as follows: 




.1 \\i \m 






















Here again a slight retardation in the advent of the 
metamorphosis is observable in the southern portion. 

There would seem to be a difference in the time of the 
change between the two years of fifteen days, 1905 
being by that much the later. But with points 
of reference themselves thirty days apart, it is 
possible the two more nearly coincided than here ap- 

Unlike the ochre of the light regions generally, which 
suggest desert pure and simple, the chocolate-brown 
precisely mimicked the complexion of fallow ground. 
When we consider the vegetal-like blue-green that it 
replaced, and remember further the time of year at 
which it occurred upon both these Martian years, we 
can hardly resist the conclusion that it was something 
very like fallow field that was there uncovered to our 

From the recurrence of the phenomenon on two suc- 
cessive years, it is likely that it annually takes place. 




chap, xi VEGETATION 127 

That it is seasonal can scarcely be doubted from the 
timeliness of its occurrence, and that different portions 
of its terrane successively underwent their metamor- 
phosis shows further that it followed a law peculiar 
to the planet, to which we shall be introduced when we 
come to consider the phenomena of the canals. 

Instances of relative hue in different dark patches 
corroboratory of seasonal variation, and therefore of 
vegetal constitution, might easily be adduced. Thus, 
in 1905 during the summer of the northern hemisphere, 
the Mare Acidalium was notably darker than the Mare 
Erythraeum to the north of it, which is what the law 
of seasonal variation would require, since it was June 
in the one, December in the other at the time. But we 
need not to add example to example or proof to proof, 
for there are no phenomena that contradict it. We 
conclude, therefore, that the blue-green areas of Mars 
are not seas, but areas of vegetation. Just as reasoning 
to a negative result drifts us to the first conclusion, so 
reasoning to a positive one lands us at the second. 



TI7ITII the vanishing of its seas we get for the first 
time solid ground on which to build our Martian 
physiography. The change in venue from oceans to 
land has produced a complete alteration in our judg- 
ment of the present state of the planet. It destroys 
the analogy which was supposed to exist between Mars 
and our earth, and by abolishing the actuality of oceans 
there, seems, metaphorically, to put us at first all the 
more at sea in our attempt to understand the planet. 
But looked at more carefully, it turns out to explain 
much thai was obscure, and in so doing gives us at once 
a wider view of the history of planetary evolution. 

The trait concerned is cosmic. (Study of the several 
planets of our solar system, notably the Earth, Moon, 
and Mars, reveals tolerably legibly an interesting phase 
of a planet's career, which apparently must happen 
t<> .-ill such bodies, and evidently has happened or is 
happening to these three: the transition of its sur- 
face from a terraqueous to a purely terrestrial con- 
dition. The terraqueous state is well exhibited by 
our own earth at the moment, where lands and 


chap, xn TERRESTRIALITY 129 

oceans share the surface between them. The ter- 
restrial is exemplified by both the Moon and Mars ; 
on whose surfaces no bodies of water at present exist- 
That the one state passes by process of development 
into the other I shall now give my reasons for 

In the first place the appearance of the dark markings 
both on the Moon and Mars hints that though seas 
no longer, they were seas once upon a time. On the 
moon, not only does their shape suggest this previous 
condition, but the smooth and even look of their sur- 
faces adds to the cogency of the inference. More im- 
portant, however, than either of these characteristics, 
and confirmatory of both, is the fact that the great 
tracts in question seem to lie below the level of the cor- 
rugated surface, which is thickly strewn with volcanic 
cones. Their level and their levelness fay in explana- 
tion into one another. The first makes possible the 
former presence of water; the second speaks of its 
effect. For their flat character hints that these areas 
were held down at the time when the other parts of 
the surface were being violently thrown up. That 
they can themselves be cooled lava flows, their extent 
and position seem enough to negative ; to say nothing 
of the fact that they should in that case lie above, 
not below, the general level. Something, therefore, 
covered them during the moon's eruptive youth and 

1:50 MAKS AND ITS CANALS chap, xn 

disappeared later. Such superincumbence may well 
have been water, under which the now great plains lay- 
then as ocean bottoms. Deep-sea soundings in our 
own oceans betray an ocean floor of the same exten- 
sive sort, diversified as on the moon. To call the 
lunar maria seas may not be so complete a misnomer 
after all ; but only a resurrecting in epitaph what was 
the truth in its day. 

( )nly doubtfully offered here for the Moon, for 
Mars the inference seems more sure. Here again the 
dark regions not only look as they should had they 
had an earlier history, but they, too, seem to lie below 
the level of the surface round about. When they pass 
over the terminator they invariably show as flatten- 
ing upon it, as if a slice of the surface had been pared 
off. Such profile in such pass is what ground at a 
lower level would present. Undoubtedly a part of the 
seeming depression is due to relative absence of irradi- 
ation consequent upon a more sombre tint, but loss 
of light hardly seems capable of the whole effect. In 
the ease of Mars, then, as with the Moon, a mistaken 
inference builded better than it knew, if, indeed, we 
should rightly consider an inference to be mistaken 
which on half data lands us at the right door. 

From the aspects of the dark regions we are led, 
then, to regard Mars as having passed through that stage 
of existence in which the earth finds itself at the mo- 

chap, xii TEKRESTRIALITY 131 

ment, the stage at which oceans and seas form a feature 
of its landscape and an impediment to subjugation of 
its surface in its entirety. What once were ocean beds 
have become ocean bottoms devoid of that which 
originally filled them. 

(That the process of parting with a watery envelop 
is an inevitable concomitant of the evolution of a planet 
from chaos to world, we do not have to go so far afield 
as Mars and the Moon for testimony. Scrutiny reveals 
as much in the history of our own globe. Two sign- 
posts of the past, one ^geologic, the other paleonr 
tologic, point unmistakably in this direction.) The 
geologic guides us the more directly to the goal. 

Study of the earth's surface reveals the preponderat- 
ing encroachment of the land upon the sea since both 
began to be, and demonstrates that, except for local 
losses, the oceans have been contracting in size from 
archaic times. So much is evidenced by the successive 
places upon which marine beds have been laid down. 
This suggests itself at once as a theoretic probability 
to one considering the matter from a cosmic standpoint, 
and it is therefore the more interesting and conclusive 
that, from an entirely different departure-point, it 
should have been one of the pet propositions of the 
late Professor Dana, who worked out conclusively the 
problem for North America, and published charts 
detailing the progressive making of that continent. 



CH.vr. xii 

So telling is this reclaiming by nature of land from 
the sea that it will be well to follow Dana a little into 
detail, as the details show effectively the continuity of 
the process acting through aeons of geologic time. At 

Map of North America at the close <>f Archeean time, showing approximate]} 
the areas <>f <lry land. | From I ana's " Manual of Geology.") 

the beginning of the Archaean age, or, in other words, 
;it the epoch when stratified beds were first laid down. 
the earth reached a turning-point in its history. 
Erosion, superficial and sub-arial, then set in to help 
restrict the domain of the sea. At this juncture North 
America consisted of a sickle of terrane inclosing Hud- 

chap, xii TERKESTRIALITY 133 

son's Bay and coming down at its apex to a point not 
much removed from where Ottawa now stands, in 
about latitude 45 a Labradorian North America 
only. This, the kernel of the future continent, curi- 
ously symbolized the form that continent was later to 
take. For its eastern edge was roughly parallel to the 
present Atlantic coastline, although much within and 
to the north of it, while its western one was similarly 
aligned afar off to the now Pacific slope. Besides this 
continent proper, the Appalachian, Rocky Mountain, 
Sierra Nevada, and Sierra Madre chains stood out of the 
ocean in long, narrow ridges of detached land, outlining 
in skeleton the bones of the continent that was to be. 
The Black Hills of Dakota and other highlands made 
here and there islets in the sea. 

Much the same backbone-showing of continents yet 
to be filled out was true of Europe, Asia, and South 
America. In Europe the northern countries constituted 
all that could be called continental land. Most of 
Norway, Sweden, Finland, Lapland, existed then, while 
the northern half of Scotland, the outer Hebrides, por- 
tions of Ireland, England, France, and Germany stood 
out as detached islands. From this, which is a fair 
sample of the proportion of land then to land now over 
the other continents so far as they are geologically 
known, we turn to consider more in detail the history 
of North America. 

134 MARS AND ITS CANALS chap, xn 

By the time the Upper Silurian period came in, the 
Appalachian highlands there had been greatly extended 
and joined to the Labradorian mainland by continuous 

North America :it the opening of the Upper Silurian. (From Dana's 
"Manual of Geology.") 

territory; otherwise, no important addition had oc- 
curred, though islands emerged in Ohio, Kentucky, and 

At the commencement of the Carbonic era what are 
now the Middle states had begun to fill up from the 
north, and Newfoundland, from a small island in the 
I pper Silurian, had become a great promontory of 
Labrador, while the Eastern states region and Nova 
Scotia had risen into being. The movements closing 




Paleozoic time upheaved from low islands the Ap- 
palachian chain. The earth's crust here crumpled 
by contraction upon itself ; and the movement ended, 

Map of North America after the Appalachian Revolution. (From Dana's 
" Manual of Geology.") 

as Dana says, by making dry land of the whole eastern 
half of the continent, along substantially its present 

Mesozoic time was the period of the making of the 
West. It was an era of deposition and coincident sub- 
sidence, when the western land had its nose just above 
water at one moment to be submerged the next. 
Though on the whole this part of the continent was 
emerging, the fact was that, synchronously with the 




sinking of the sea, much of the land from time to time 
sank too. The contraction which raised the Appala- 
chian Mountains at the beginning of the period and that 

North America in the Cretaceous period. (From Dana's " Manual of 

of the Rockies at its close overdid the necessities of the 
case and caused subsidence elsewhere. The south- 
eastern portion of the continent suffered most, the West 
on the whole materially gaining. In the Triassic and 
Jurassic eras the gain was pronounced; it occurred in 
the Cretaceous also, but with much alternation of loss. 
Finally, at the close of the Cretaceous, the continent, 
except for a prolonged Gulf of Mexico and vast internal 

lakes, was substantially complete. 
The filling up of these lakes and the reclaiming of 



land from the Gulf of Mexico constituted the land- 
making work of Tertiary times. The extent of the 
lakes in the Eocene era is held to show that the general 

Map of North America, showing the parts under water in the Tertiary Era ; 
the vertically lined is the Eocene. (From Dana's " Manual of Geology.") 

level of the mountain plateau was low and rose later. 
So that the gain by the land at this time was greater 
than the map allows to appear. By the beginning of 
the Quaternary epoch the continents had assumed 
their present general area, and since then their internal 
features have alone suffered change. 

A similar rising from the sea fell to the lot of Europe, 
though it has not been detailed with so much care. The 
skeleton of that continent was at the beginning of 
depositary time much what it is to-day, but a great in- 

138 MARS AND ITS CANALS chap, xn 

land sea occupied the centre of it, which, as time went 
on, was gradually silted in and evaporated away, 
notably during the Upper Silurian period. 

From all this it is pretty clear that, side by side with 
alternating risings and sinkings of the land, there was 
a tolerably steady gain in the contest by which dry 
ground dispossessed the sea. We may, of course, 
credit this to a general deepening of the ocean bottoms 
due to crumpling of the crust, but we may also impute 
it to a loss of water, and that the latter is, at least for 
a part, in the explanation the condition of the Moon 
and Mars makes probable. 

Paleontology has the same story of reclamation to 
tell as geology, and with as much certainty, though its 
evidence is circumstantial instead of direct and speaks 
for the growing importance of the land in the globe's 
economy since the beginning of depositary time, and 
thus inferentially to its increasing extent. Fossil 
remains of the plants and creatures that have one after 
the other inhabited the earth show that the land has 
been steadily rising both in floral and faunal estimation 
as a habitat from the earliest ages to the present day. 
The record lies imprinted in the strata consecutively 
laid down, and except for gaps reads as directly on in 
bettering domicile as in evolutionary development. 

In Archaean times we find no undisputed evidence 
of life either vegetal or animal. But beds of graphite 

chap, xii TERRESTRIALITY 139 

and of limestone point to the possible existence of both. 
Even anthracite has been found in Archaean rocks in 
Norway and also in Rhode Island. Whether Dawson's 
Eozoon Canadense be a rhizopod or a crystal, doctors 
of science disagree. Dana, while admitting nothing 
specific, deems it antecedently probable that algae 
and later microscopic fungi related to bacteria existed 
then, living in water well up toward the boiling-point. 
Indeed, it is practically certain that invertebrate life 
existed, because of its already well-developed character 
in the next era. The like antedating is inferable for 
the whole record of the rocks. Relatively their history 
is undoubtedly fairly accurate, but absolutely it must 
be shifted bodily backward into the next preceding era 
to correspond with fact not yet unearthed. 

In the Lower Cambrian, when first the existence of 
life becomes a certainty, that life, so far as known, was 
wholly invertebrate and wholly marine; rhizopods 
(probably), sponges and corals, echinoderms, worms, 
brachiopods, mollusks, and crustaceans grew amid 
primitive seaweed and have left their houses in the shape 
of shells while perishing themselves. Their tracks 
too have thus survived. The trilobites, crustaceans 
somewhat resembling our horseshoe crab, were the 
lords of the Cambrian seas and marked the point to 
which organic evolution had then attained. Their 
aquatic character as well as their simple type is shown 

140 MARS AM) ITS .CANALS chap, xn 

by their thoracic legs having each a natatory append- 

In the next era, the Lower Silurian, the fauna and 
flora were still marine, although of a higher order than 
before, and in the Trenton period, the upper part of the 
era, the earliest vertebrates, fishes, come upon the scene : 
ganoids and possibly sharks. Nothing terrestrial of 
this period has yet with certainty been unearthed in 
America. Europe would seem to have either been more 
advanced then or better studied since, for there the 
first plant higher than a seaweed has been dug up, one 
of a fresh-water genus betokening the land; while in 
keeping with this the first insect, an hemipter, also has 
been disinterred. Both the geography and the life of 
the Kopaleozoic period Dana styles "thalassic." 

Neopaleozoic time, beginning with the Upper Silu- 
rian, marked the emergence of the continents, and fol- 
lowing them the emergence of life from the water on to 
this land. In the lower beds of the Upper Silurian in 
America we find only the aquatic forms of previous 
strata, but in a higher one we come in marshes upon 
plants related to the equiseta or horsetails. In 
England land plants appear for the first time in these 
latest Silurian beds and in the schists of Angers have 
been preserved ferns. In both the old world and the 
new fossil fishes are found and the oldest terrestrial 
species of scorpions. But the great bulk of forms was 

chap, xii TERRESTKIALITY 141 

still marine; corals, crinoids, brachiopods, trilobites 
constituting the principal inhabitants. At this time 
the seas were warm, having much the same temperature 
between 65 and 80 north as between 30 and 45; 
the prevalence of a general temperate tropicality being 
shown by the fact that the common tropical chain 
corals lived in latitude 82 north. 

In the Devonian era, the Old Red Sandstone, fishes 
grew and multiplied, increasing in size apparently 
through the era, and in the last period of it reaching 
their culminating point. These pelagic vertebrates 
much surpassed in structure the terrestrial population 
of the time, which was of a low type and consisted of 
invertebrates such as myriapods, spiders, scorpions, 
and insects; for the land was only making. In the 
mid-Devonian, forests of a primitive kind covered such 
country as there, was, an amphibious land, composed 
of jungles and widespread marshes. Tree ferns made 
the bulk of the vegetation, but among them grew also 
cycads and yews. Mammoth may-flies flitted through 
the gloom of these old forests, but no vertebrate as yet 
had left the sea. 

Following upon the Old Red Sandstone were laid 
down the Carbonic strata, and with the Carbonic en- 
tered upon the scene the advance scouts of an army 
of progress evolutionarily impelled to spy out the land 
the first amphibians. They made their debut in the 

14:2 MARS AND ITS CANALS chap, xn 

Subcarboniferous section of the era, the oldest of the 
three periods into which the Carbonic is divided, 
crawling out of the sea to return again and leaving but 
footprints at first on the sands of time. In the second 
period, the Coal-measures proper, they ventured so far 
as to leave their skeletons on terra firma, or rather 
infirma, while their tracks there show them to have 
been now in great numbers. In this manner the an- 
cestors of the oldest land inhabitants began to struggle 
out of the sea. In the Permian, the third and latest 
period of paleozoic times, we find their descendants 
established in their new habitat, for in it we come upon 
the first reptiles. Such possession marks a distinct 
step up in function as in fact, for while amphibians 
visited dry land, reptiles made it their home. The 
getting out of the water had now, in the case of the 
more evolved forms, become an accomplished fact. 
The reptiles were, indeed, the lowest and most general- 
ized of their class, Rhynchocephalians, ''beak-headed" 
species that by their teeth proclaim their marine 
origin and their relationship to the great amphibians 
that still felt undecided where to stay. Meanwhile, 
in Europe dragon-flies, two feet across, possessed the 
air; while amphibians there, as here, ancestrally pre- 
ceded reptiles in occupying the land. 

Mesozoic times were, par excellence, the age of mon- 
sters; for the Triassic (the New Red Sandstone), 

chap, xii TERRESTRIALITY 143 

Jurassic and Cretaceous eras marked the reign of the 
reptiles. Great dinosaurs sleep still in the Triassic 
strata of the Atlantic border and in the Jurassic of the 
Western states, to be unearthed from time to time 
and be given mausolea in our museums. Gigantic 
they were and very literally possessed the earth. In 
Europe they were substantially as in America during 
these mesozoic eras, and showed their dominance by 
long survival in time as well as world-wide distribution 
in space; for they lived all the way from Kansas to 
New Zealand and from the Trias to the Upper Cre- 
taceous. It is supposed by Professor Osborn that many 
of them, like the herbivorous brontosaurus, waded in 
marshes, not wholly unlike in habit to the modern 
hippopotamus. Others were land-stalking carnivores, 
like the megalosaurs of a little later date. Of enormous 
size, the largest exceeded any animal which has ever 
lived, the whales alone excepted; the biggest, the 
atlantosaurus and the brontosaurus, reaching a length 
of sixty feet. For all their bulk they had scant brains, 
just enough to enable them to feed and wallow, prob- 
ably. It is interesting to note that many of the rep- 
tiles, the less adventurous, apparently reverted to the 
sea. For though the crocodilians existed already in 
the Trias, the plesiosaurians did not come in till the 
Middle Trias in Europe, and the sea-serpents (mosasau- 
rus) till the Upper Cretaceous. 

144 MARS AND ITS CANALS chap, ui 

Though the dinosaurs dominated life in those days, 
higher forms, their descendants, unnoticed were gradu- 
ally creeping in, eventually to supplant them. For 
brain was making its way unobtrusively in the earliest 
of the mammals, diminutive creatures at first and of the 
lowest type. First appearing in the Trias as some- 
thing approaching the missing link between reptiles 
and mammals, they later developed into monotremes 
and marsupials, not rising in differentiation above the 
latter order to the end of Mesozoic times. And this 
both in the old world and the new. In the Jurassic, too, 
flying lizards and the first birds appeared, showing 
their pedigree in their teeth. 

With Cenozoic times we come upon the first true or 
placental mammals with their culmination up to date 
in man. In the Eocene they were of a primitive type; 
they were also of a eoniprehensive one, fitted to eat any- 
thing. From this they specialized, some evolving and 
some on (he whole devolving; the whale, for instance, 
taking to the water in the Eocene through the same 
degenerate proclivity that had characterized the sea- 
saurians ages before. The earth was growing colder, 
though still fairly warm, and with the fall in tempera- 
ture the higher types of life antithetically rose, evolu- 
tion gradually fitting them to cope with more advanced 
conditions. In this manner did the land supplant the 
sea as the essential feature of the earth's surface, first, 

chap, xii TERRESTRIALITY 145 

in coming into being, and then, by offering conditions 
fraught with greater possibilities, as the habitat of the 
most advanced forms of life, both plants and animals. 

The possibility of advance in evolution was largely 
due to the fact that the land did thus supplant the sea. 
Spontaneous variation, the as yet unexplained pri- 
mum mobile in the genesis of species, is probably to be 
referred to chemism and is likely later to receive its 
solution at the hands of that science. In the meanwhile 
it is evident that unless the variation obtain encourage- 
ment from the environment no advance in type occurs. 
Now the land offers to an organism sufficiently evolved 
to benefit by it, opportunities the sea does not possess. 
First of these, undoubtedly, is the care it enables to be 
given to the young. To cast one's brood upon the 
waters is not the best method of insuring its bringing up. 
There is too much of the uncertainties of wave and cur- 
rent to make the process a healthy one, and even when 
attached to rocks and seaweed, the attachment to a 
mother is to be preferred. Without a period of in- 
fancy, when the young is unable to do for itself, no great 
development is possible. In the only striking excep- 
tion, the case of the whales, dolphins, and porpoises, 
size has probably counted for much in the matter, while 
the development of the cetaceans is far behind that 
of the majority of land mammals. 

Change of place, not in distance, but in variety, is 

146 MARS AND ITS CANALS chap.xh 

another factor. The sea is same as a habitat, one square 
mile of it being much like another, except for gradually 
changing temperature. The land, on the other hand, 
from its accidented surface, presents all manner of 
diversity in the conditions. And the more varied the 
conditions to which the organism is exposed, the greater 
its own complexity must be to enable it to meet them. 

That the terrestrial stage of planetary development 
is subsequent to the terraqueous one, and must of 
necessity succeed it if the latter ever exist on a body, 
follows from the loss of internal heat on the one hand 
and from the kinetic theory of gases on the other. To 
which of the two to attribute the lion's share in the 
business is matter for doubt; but that both must be 
concerned in it we may take for certain. 

So long as the internal heat suffices to keep the body 
fluid, the liquid itself sees to it that all interstices are 
filled. As the heat dissipates, the body begins to solidify, 
starting with the crust. For cosmic purposes it un- 
doubtedly still remains plastic, but cracks of relatively 
small size are both formed and persist. Into these the 
surface water seeps. With continued refrigeration the 
crust thickens, more cracks are opened and more water 
given lodgmenl within, to the impoverishment of the 
The process would continue till the pressure of 
the crust itself rendered plastic all that lay below, be- 
yond which, of course, no fissures could be formed. 

chap, xii TERRESTRIALITY 147 

How competent to swallow all the seas such earth cuti- 
cle cracks may be we ignore ; for we cannot be said to 
know much of the process. We can only infer that to 
a certain extent internal absorption of surface seas 
must mark a stage of the evolution by which a star 
becomes a world and then an inert mass, one of the 
dark bodies of which space is full. 

Of the other means we know more. We are certain 
that it must take place, though we are in doubt as to 
the amount it has already accomplished. This method 
of depletion is by the departure of the water in the form 
of gas, in consequence of the molecular motions. If we 
knew the temperature and the age of Mars and also 
the amount of atmosphere originally surrounding it, 
we could possibly predicate its state. Reversely, we 
can infer something as to age and temperature from 
its present condition. 



DOTH for their evidence and their extent the great 
ochre stretches of the disk claim attention first. 
Largely unchangeable, these show essentially the same 
day after day and from the year's beginning to its end. 
In hue they range from sand color to a brick red; some 
parts of the planet being given to the one tint, some 
to the other. It is to the latter that the fiery tint of 
Mars to the naked eye is due. The differences in com- 
plexion arc local and peculiar, both in place and time. 
For though saffron best paints the greater part of the 
light areas, certain localities present at times a red 
like that of our red sandstone. Hellas is one of these 
ruddy regions and Aeria another. It is only on occasion 
that they thus show, and to what to assign their varia- 
bility is as yet matter of conjecture. Possibly it is 
owing to Martian meteorologic condition; possibly 
to something else. But whatever its origin, the change 
is not so much contradictory of, as supplementary to, 
the general fact of unalterableness, which is after all 
the basic trait about them and the keynote to their 



Land the ochre regions have generally been taken for, 
and land they still make good their claim to be con- 
sidered. For the better they are seen, the greater the 
ground for the belief. Indeed, they seem to be noth- 
ing but ground, or, in other words, deserts. Their 
color first points them out for such. The pale salmon 
hue, which best reproduces in drawings the general 
tint of their surface, is that which our own deserts wear. 
The Sahara has this look ; still more it finds its coun- 
terpart in the far aspect of the Painted Desert of 
northern Arizona. To one standing on the summit of 
the San Francisco Peaks and gazing off from that iso- 
lated height upon this other isolation of aridity, the 
resemblance of its lambent saffron to the telescopic 
tints of the Martian globe is strikingly impressive. 
Far forest and still farther desert are transmuted by 
distance into mere washes of color, the one robin's-egg 
blue, the other roseate ochre, and so bathed, both, in 
the flood of sunshine from out a cloudless burnished 
sky that their tints rival those of a fire-opal. None 
otherwise do the Martian colors stand out upon the 
disk at the far end of the journey down the telescope's 
tube. Even in its mottlings the one expanse recalls 
the other. To the Painted Desert its predominating 
tint is given by the new red sandstone of the Trias, 
the stratum here exposed; and this shows in all its 
pristine nakedness because of the lack of water to clothe 

lf>0 MARS AND ITS CANALS chap, xm 

it with any but the sparsest growth. Limestones that 
crop out beside it are lighter yellow, whitish and steel- 
maw and seen near give the terrane the look of a 
painter's palette. Seen from far they have rather the 
tint of sand; and the one effect, like the other, is Mar- 
tian in look. And as if to assimilate the two planetary 
appearances the more, the thread of blue-green that 
attention traces athwart the Painted Desert marks 
the line of cottonwoods along the banks of the Little 
Colorado River deserts both, if look be any guarantee 
of character, with verdure banding them. 

In other ways these earthly deserts offer a parallel 
to the Martian. No desert on the Earth is absolutely 
devoid of life of some kind, vegetal and animal. The 
worst conditioned are not what one is taught in child- 
hood to believe a desert to be a vast waste of sand, 
with a camel and a palm thrown in to heighten the 
sterility. In all Saharas outside of the pages of the 
school books some vegetation grows, though it is com- 
monly not of a kind to boast of, being rather a succes 
d'estime, as sagebrush, cacti, and the like. But what 
is of interest here in the connection is its color. For 
it is commonly of a more ochreish tint than usual, in 
keeping with its surroundings, a paling out of the green 
to something more tawny, indicating a relative reduc- 
tion of the chlorophyll and an increase of the lipo- 
chromes in the tissues of the plant, since the one gives 


the green tint to the leaves, the other the yellow. As 
this vegetation, poor as it is, has its annual history, 
it must alter the look of the desert at times and pro- 
duce precisely those slight variations in tint observable 
on Mars in like circumstance. 

The Arizona desert dates from no further back than 
early Tertiary times, as the limestone of the Cretaceous 
there present shows. Water then stretched where 
desert now is, and the limestone beds were laid down in 
it. How old the Martian Saharas are we have no means 
of knowing. But one thing we may predicate about 
both : a desert is not an original, but an acquired, condi- 
tion of a planet's surface, demonstrably so in the case 
of a planet which has had a sedimentary epoch in its 
life-history. In the Arizona desert the surface is com- 
posed of depositary rocks of Mesozoic times, except 
where lava streams have flowed down over it since 
then. The land, then, was once under water, and 
cannot but have been fertile for some time after it 

But we are not left to inference in the matter, how- 
ever good that inference may be. A little to the south 
of the Painted Desert, in the midst of the barren plateau 
of northern Arizona, of which the former makes a part, 
stand the remains of a petrified forest. Huge chalced- 
ony trunks of trees, so savingly transmuted into stone 
that their genus is still decipherable, lie scattered here 

152 MARS AND ITS CANALS chap, xm 

over the barren ground in waste profusion, one of them 
still spanning a canon just as it fell in that, to it, de- 
structive day of a far prehistoric past. The rock 
stratum on which their remains lie is of Triassic and 
Cretaceous times and the petrifications show that in 
the Cretaceous a stately forest overspread the land. 
In those days at least the spot was fertile where now 
spa isc sagebrush and cacti find a living hard. Not here 
alone where the blocks are so conspicuous as to invite 
their carrying away is a former flourishing growth of 
vegetation attested, but over large adjoining areas of 
desert search has brought the like past tenancy to light. 
Fragments of what once were trees have been picked 
up in the Little Colorado basin and in the neighbor- 
hood of Ash Fork, on both sides, that is, of the present 
forest crown that covers the higher part of the plateau 
from which rise the San Francisco Peaks. In the blue 
distance the mountains look down verdure-clad upon 
a now encircling waste, but one which in earlier eras 
was as pine-bearing as they. Their lofty oasis is all 
that is now left of a once fertile country; the retreat 
of the trees up the slopes in consequence of a dimin- 
ishing rainfall, until a rise of two thousand feet from 
what once was timber-land is necessary to reach the 
tree-line of today, being typical of desert lands, and 
testifying to greater aqueous affluence in the past. 
In the same manner streams descend from the cedar- 


clad range of the Lebanon to lose themselves in the 
Arabian desert just without the doors of Damascus; 
and Palestine has desiccated within history times. 
Palestine, a land once flowing with milk and honey, 
can hardly flow poor water now, and furnishes another 
straw to mark the ebbing of the water supply. 

This making of deserts is not a sporadic, accidental, 
or local matter, although local causes have abetted or 
hindered it. On the contrary, it is an inevitable result 
of planetary evolution, a phase of that evolution which 
follows from what has been said in Chapter XII on 
the abandonment of a planet by its water. Deserts 
are simply another sign of the same process. The very 
aging which began by depriving a body of its seas 
takes from it later its forest and its grass. A growing 
scarcity of water is bound to depauperate the one, as it 
depletes the other. We have positive proof of the 
action in our own deserts. For these bear testimony, 
in places at least, to not having always been so, but 
to have gradually become so within relatively recent 
times. But we have more general proof of the action 
from the position occupied on the earth's surface by its 

The significant fact about the desert-making so 
stealthily going on is that only certain zones of the 
earth's surface are affected. Those belting the two 
tropics of Cancer and Capricorn, for several degrees 

15-1 MARS AND ITS CANALS chap, xin 

on either side of them, most exhibit the phenomenon. 
Such positioning of the deserts is not due to chance. 
Directly, of course, desertism is due to dearth of rain. 
This in turn depends on the character and condition 
of the winds. If a wind laden with moisture travel 
into a colder region of the globe, its moisture is pre- 
cipitated in rain and we have a fertile country; if it 
voyage into a warmer clime it takes up what little 
moisture may be there already and a desert is the 

Now our system of winds is such as to produce a fall 
of rain for the different latitudes, as tabulated by 
Supan, thus: 

Zone I 40N-27N Little rain in summer but much in winter. 
1 1 27 N-19 N Little rain at all seasons. 

III 19 X- 7 X T Little rain in winter but much in summer. 

IV 7 X- 1 N Abundant rain at all seasons. 

V 1 N-17 S Little rain in winter but much in summer. 
VI 17 S-30 S Little rain at all seasons. 
V 1 1 .'30 S-,35 S Little rain in summer but much in winter. 

Zones II and VI, the zones of minimum rainfall, are 
also those in which the deserts occur. The northern 
one t inverses southern California, Arizona, New Mexico, 
the Sahara. Arabia, and the Desert of Gobi; the south- 
ern. Peru, the South African veldt, and central Aus- 
tralia. The belts are wavy bands which by their 
form betray both a general underlying trend to drought 


at these parallels and also the effect of local topography 
in the matter. 

From being distributed thus in belts, it is evident that 
the deserts are general globe phenomena, and from their 
being found only in the zones of least rainfall, that the 
earth has itself entered, though not far as yet, upon 
the desert stage of its history. Once begun, the desert 
areas must perforce spread as water becomes scarce, 
invading and occupying territory in proportion as the 
rainfall there grows small. 

Now the axial tilt of Mars is almost exactly the same 
as that of our Earth, the latest determinations from 
the ensemble of measures giving 24 for it. Here, then, 
we have initial conditions reproducing those of the 
earth. But from the smaller size of the planet that 
body would age the earlier, since it would lose its inter- 
nal heat the more rapidly, |ust as a small stone cools 
sooner than a larger one. On general principles, 
therefore, it should now be more advanced in its plan- 
etary career. In consequence, desertism should have 
overtaken more of its surface than has yet happened 
on earth, and instead of narrow belts of sterility we 
should expect to find there Saharas of relatively vast 

Now, such a state of things is precisely what the 
telescope reveals. The ochre tracts occupy nine tenths 
of the northern hemisphere and a third of the southern. 

156 MARS AND ITS CANALS chap, xm 

Three fifths, therefore, of the whole surface of the 
planet is a desert. 

Of cosmic as well as of particular import is the corre- 
lation thus made evident between the physical prin- 

Desert areas. 

oiples that effect the aging of a planet and the aspect 
Mars presents. Experimental corroboration of those 
laws is thus afforded, while, reversely, confidence in 
their applicability is increased. With continued ob- 
servation the planet appears more desiccate as im- 
proved conditions bring it nearer. Dry land as it 



was thought to be proves even drier, something which 
lacks water for the ordinary necessities of a living 
The picture the planet offers to us is thus arid beyond 

Desert areas. 

present analogue on Earth. Pitiless as our deserts 
are, they are but faint forecasts of the state of things 
existent on Mars at the present time. Only those who 
as travelers have had experience of our own Saharas 
can adequately picture what Mars is like and what so 
waterless a condition means. Only such can understand 

158 MARS AND ITS CANALS chap, xm 

what is implied in having the local and avoidable thus 
extended into the unescapable and the world-wide ; and 
what a terrible significance for everything Martian lies 
in that single word : desert. 



TF, now, we review with the mind's eye the several 
features of Mars which we have surveyed with the 
bodily one, we shall be surprised to find to what they 
commit us. Suggestive as each is considered by itself, 
the ensemble into which they combine proves of mul- 
tiplicate force in its implication. For each turns out 
to fit into place in one consistent whole, a scheme of 
things in which are present all the conditions necessary 
to the existence and continuance of those processes 
which constitute what we call life. In short, we are 
conducted with a cogency, which grows as we consider 
it, to the conclusion that Mars is habitable. 

Two ways of appreciating this cogency are open to us. 
We may treat it with the simple reasoning of common- 
sense, as we should a dissected map or a piece of ma- 
chinery in which we realize we are right when the 
several parts at last fit together and the picture stands 
revealed or the machine works. Or we may subject 
the evidence to quantitative estimates for and against 
by the doctrine of probabilities, and thus evaluate 
the chances of its being correct. Consciously or un- 

^~~ 159 

160 MARS AND ITS CANALS chap, xiv 

consciously, this is what we are about in our decisions 
every day of our lives. At the one end of the line are 
those skillful judgments where the balance is so keen- 
edged that the least overweight on the one side dips the 
scales to a conclusion. At the other extremity stand 
those deductions which we usually speak of as proved, 
such as the law of gravitation. But both assurances 
rest really upon probability and differ only in degree. 
What we mean by proof of anything is that a suppo- 
sition advanced to account for it explains all the facts 
and is not opposed to any of them, and that the balance 
of probability in consequence is very largely in its favor. 

Now, if several pieces of evidence, distinct in their 
origin, concur to a given conclusion, the probability 
that thai conclusion is correct is far greater than what 
results from each alone; and mounts up soon to some- 
thing much exceeding what bettors at races call cer- 
tainty odds. However unversed the average man may 
be in calculating the probability, he recognizes the fact 
in his dealings with his fellows by the way he attaches 
weight to concurrent testimony. It is such concurrent 
evidence that we have now to consider. To this end 
we will marshal the several facts ascertained in a sum- 
marized list for their easier intercomparison. 

These facts are: 

(1) Mars turns on its axis in24h. 37 m. 22.65 s. with 
reference to the stars, and in 24 h. 39 m. 35.0 s. (as a 

chap, xiv SUMMARY 161 

mean) with regard to the Sun. Its day, therefore, 
is only about forty minutes longer than ours. 

(2) Its axis is tilted to the plane of its orbit by about 
23 59' (most recent determination, 1905). This gives 
the planet seasons almost the counterpart of our own 
in character; but in length nearly double ours, for 

(3) Its year consists of 687 of our days, 669 of its 

(4) Polar caps are plainly visible which melt in the 
Martian summer to form again in the Martian winter, 
thus implying the presence of a substance deposited 
by cold. 

(5) As the polar caps melt, they are bordered by a 
blue belt, which retreats with them. This excludes the 
possibility of their being formed of carbon dioxide, and 
shows that of all the substances we know the material 
composing them must be water. 

(6) In the case of the southern cap, the blue belt has 
widenings in it in places. These occur where the blue- 
green areas bordering upon the polar cap are largest. 

(7) The extensive shrinkage of the polar snows shows 
their quantity to be inconsiderable, and points to 
scanty deposition due to dearth of water. 

(8) The melting takes place locally after the same 
general order and method, Martian year after year, 
both in the south cap, 

(9) And in the north one. This is evidenced by the 

102 MARS AM) ITS CANALS chap, xiv 

recurrence of rifts in the same places annually in each. 
The water thus let loose can, therefore, be locally 
counted on. 

(10) That the south polar cap is given to greater 
extremes than the north one, implies again, in view 
of the eccentricity of the orbit and the tilt of the axis, 
that deposition in both caps is light. 

(11) The polar seas at the edges of the caps being 
temporary affairs, the water from them must be fresh. 

(12) The melting of the caps on the one hand and 
their reforming on the other affirm the presence of 
water vapor in the Martian atmosphere, of whatever 
else that air consist. 

(13) Since water vapor is present, of which the 
molecular weight is 18, it follows from the kinetic 
theory of gases that nitrogen, oxygen, and carbonic 
acid, of molecular weights 28, 32, and 38 respectively, 
are probably there, too, owing to being heavier. 

(14) The limb-light bears testimony to this atmos- 

(15) The planet's low albedo points to a density 
for the atmosphere very much less than our own. 

( Hi) The apparent evidence of a twilight goes to con- 
firm this. 

(17) Permanent markings show upon the disk, prov- 
ing that the surface itself is visible. 

(IS) ( )utside of the polar cap the disk is divided into 

chap, xiv SUMMAEY 163 

red-ochre and blue-green regions. The red-ochre 
stretches have the same appearance as our deserts 
seen from afar, 

(19) And behave as such, being but little affected 
by change. 

(20) The blue-green areas were once thought 
to be seas. But they cannot be such, because they 
change in tint according to the Martian season, and the 
area and amount of the lightening is not offset at the 
time by corresponding darkening elsewhere; 

(21) Nor by any augmentation of the other polar 
cap or precipitation into cloud. It cannot, therefore, 
be due to shift of substance. 

(22) Furthermore, they are all seamed by lines and 
spots darker than themselves which are permanent in 
place; so that there can be no bodies of water on the 

(23) On the other hand, their color, blue-green, is 
that of vegetation; this regularly fades out, as vege- 
tation would, to ochre for the most part, but in places 
changes to a chocolate-brown. 

(24) The change that comes over them is seasonal 
in period, as that of vegetation would be. 

(25) Each hemisphere undergoes this metamor- 
phosis in turn. 

(26) That it is recurrent is again proof positive of 
an atmosphere. 

164 MARS AND ITS CANALS chap, xiv 

(27) The changes are metabolic, since those in one 
direction are later reversed to a restoration of the origi- 
nal status. Anabolic as well as katabolic processes 
thus go on there ; that is, growth as well as decay takes 
place. This proves them of vegetal origin. 

(28) The existence of vegetation shows that carbonic 
acid, oxygen, and undoubtedly nitrogen, are present in 
the Martian atmosphere, since plants give out oxygen 
and take in carbonic acid. 

(29) The changes in the dark areas follow upon the 
melting of the polar caps, not occurring until after 
that melting is under way; 

(30) And not immediately then, but only after the 
lapse of a certain time. 

(31) Though not seas now, from their look the dark 
areas suggest old sea bottoms, and when on the ter- 
m or appear as depressions (whether because really 
at a lower level or because of less illumination is not 

(32) That they are now the parts of the planet to 
support vegetation hints the same past office, as water 
would naturally drain into them. That such a meta- 
morphosis should occur with planetary aging is in 
keeping with the kinetic theory of gases. 

(33) Terminator observations prove conclusively 
thai there are no mountains on Mars, but that the 
surface is surprisingly flat. 

chap, xiv SUMMARY 165 

(34) But they do reveal clouds which are usually 
rare and are often, if not always, dust-storms. 

(35) White spots are occasionally visible, lasting 
unchanged for weeks, in the tropic and temperate re- 
gions, showing that the climate is apparently cold, 

(36) But at the same time proving that most of the 
surface has a temperature above the freezing-point. 

(37) In winter the temperate zones are more or 
less covered by a whitish veil, which may be hoar-frost 
or may be cloud. 

(38) A spring haze surrounds the north polar cap 
during the weeks that follow its most extensive melting. 

(39) Otherwise the Martian skv is perfectly clear ; 
like that of a dry and desert land, i 

The way in which these thirty-nine articles fit into 
one another to a mortised whole is striking enough at 
first sight, but becomes more and more impressive the 
more one considers it. For some are due to one kind 
of observation, some to another. In the taking they 
are unrelated; yet in the result they agree. Equally 
pregnant is the history of their acquisition. Most of 
them were detected as the outcome of observations at 
the opposition of 1894, and led to the theory which was 
published in the writer's first book on the subject. 
Others are the result of the five oppositions that have 
since occurred. These have proved entirely corrobora- 
tive of the previous ones and of the theory then deduced, 

lt>6 MARS AND ITS CANALS chap, xiy 

and that in two distinct ways: first, by the accumu- 
lated evidence they have brought to the matter along 
the old lines; and, secondly, by what they have revealed 
in new directions. Of these thirty-nine articles of 
Martian scientific faith in observation or deduction, (9), 
(10), (21), (22), (25), (27), (28), (30), (33), (35), (36), 
and (38) are in whole or part new. That continued 
scrutiny is thus corroborative of the earlier results, both 
along the old and along new lines of investigation, war- 
rants additional confidence in the conclusion. 
\ Considering, now, these counts, we see that they 
make reasonably evident on Mars the presence of: 

1 . Days and seasons substantially like our own ; 

2. An atmosphere containing water vapor, carbonic 
acid, and oxygen; 

3. Water in great scarcity; 

4. A temperature colder than ours, but above the 
Fahrenheit freezing-point, except in winter and in the 
extreme polar regions; 

5. Vegetation. 

First and foremost of these is air. In order to make 
it possible for vital processes of any sort to take place, 
the body of a planet must be clothed with an atmos- 
phere, by the modesty of nature, the old astronomers 
would have said. Such a covering subserves two pur- 
poses: it keeps out the cold of space, thus permitting 
the maintenance of a temperature sufficient to support 

chap, xiv SUMMARY 167 

life, and it affords a medium through which metabolism 
can go on. 

Now the presence of air is attested first and foremost 
by the fact of change in the Martian markings, (12), 
(13), (26), (28), and (35). The changes observed are 
conspicuous ; are both inorganic (in the case of the polar 
caps), (12), (13), and (35), and metabolic or organic, (26) 
and (28), (in the case of the blue-green areas) ; that is, 
they consist of building up as well as of pulling down 
and are planet-wide in occurrence. Such changes 
could not occur in the absence of an atmosphere. They 
show that this atmosphere consists of water vapor, (5), 
carbonic acid, and oxygen, (28). 

The limb-light, the apparent evidence of a twilight 
arc and the planet's low albedo indicate that this atmos- 
phere is thin. The appearance of the surface, (35), sug- 
gests cold, indicative again of a thin air. Such tenuity 
is in accord with what a priori principles would lead 
us to expect, and tends to show that reliance on general 
principles is here not misplaced, a point of some in- 

Lastly, the occurrence of clouds, (34), visibly floating 
and traveling over the surface, and haze at times, (38) T 
proves in another way the existence of the medium in 
which alone this could be possible? 

(Water is the next substance vital to planetary life. 
As to its actual presence the polar caps, (4)-(12), have 

lt>8 MARS AND ITS CANALS chap, sit 

most to say; as to its relative absence, the rest of the 
disk, (17) (22). The forthright conception of the polar 
caps as composed of snow and ice is borne out by further 
investigation into what could cause the observed phe- 
nomenon. Carbonic acid, the only other substance we 
know capable in any way of resembling what we sec, 
turns out not capable of producing one important de- 
tail of the caps' appearance, the blue band, (5), which 
accompanies them in their retreat. Water alone 
could do this. 

/The melting of the caps shows that water vapor must 
be a constituent of the Martian atmosphere. More- 
over, as the molecular w r eight of water vapor is less 
than that of oxygen or nitrogen or carbon dioxide, 
if the former can exist in the atmosphere of the planet, 
a fortiori must these other gases. So that from this 
we have knowledge of the possibility of the presence 
of oxygen, nitrogen, and carbon dioxide there. From 
(28) wesaw that their actual existence is demonstrated)) 
The next step is the ascertainment that the water is 
in very small amount. The extensive melting of the 
caps. (7). shows their quantity to be inconsiderable. 
which is the first fact pointing to a dearth of water. 
The second comes from the aspect and behavior of the 
reddish-ochre regions which proclaim them deserts, (is) 
and (10); the third from the detection of the char- 
acter of the blue-green areas as not seas, (20), (21), 

chap, xiv SUMMAKY 169 

and (22). In several different ways, study of these 
regions asserts their non-aquatic constitution, the 
easiest to appreciate being that they are traversed 
by permanent dark lines and other equally sedentary 
markings, (22). No bodies of water, therefore, are to 
be seen outside of the ephemeral polar seas, immediately 
surrounding the caps as they melt?) 

^This leads us to the third presence on Mars indicative 
of a living world: vegetation. The other two spoke 
of substances necessary to life, the premises in the case, 
this one of organic existence itself, its conclusion. The 
evidence consists of static testimony from the look of the 
blue-green areas, (23), and of kinematic derived from 
their behavior, (24), (25), (26), and (27). Vegetation 
would present exactly the appearance shown by them, 
and nothing that we know of but vegetation could. 
But suggestive as their appearance is, it is as nothing 
compared with the cogent telltale character of their 
behavior. The seasonal change that sweeps over them 
is metabolic, constructive as well as destructive, that is, 
and proclaims an organic constitution for them such as 
only vegetation could produce. In tint their metamor- 
phoses are those of the same substance. For the blue- 
green lapses into ochre and revives again to blue-green 
just as vegetation does on our own Earth at the proper 
season of the year, taking both the Sun and the advent 
of water into the reckoning. Furthermore, certain 


170 MARS AND ITS CANALS chap, xiv 

of the largest dark areas turn to a chocolate-brown at 
times, which is the color of fallow ground and sugges- 
tive, at least, as occurring where the blue-green at other 
seasons is the most pronounced. Lastly, the change 
occurs at the epoch at which, from a knowledge of the 
melting of the polar caps, theory demonstrates that it 
ought to take place if it be due to the action of 

That this was the case was evident from much less 
information than is forthcoming today; but what is 
significant, each new fact discovered about the planet 
goes to show that it is unquestionably true. 





T^ROM the detection of the main markings that di- 
-* versify the surface of Mars we now pass to a discov- 
ery of so unprecedented a character that the scientific 
world was at first loath to accept it. Only persistent 
corroboration has finally broken down distrust; and, 
even so, doubt of the genuineness of the phenomena 
still lingers in the minds of many who have not them- 
selves seen the sight because of the inherent difficulty 
of the observations. For it is not one where confir- 
mation may be summoned in the laboratory at will, but 
one demanding that the watcher should wait upon the 
sky, with more than ordinary acumen. This latter- 
day revelation is the discovery of the canals. 

Quite unlike in look to the main features of the plan- 
et's face is this second set of markings which traverse 
its disk, and which the genius of Schiaparelli disclosed. 
Unnatural they may well be deemed ; for they are not 
in the least what one would expect to see. They 
differ from the first class, not in degree, but in kind ; 
and the kind is of a wholly unparalleled sort. While 
the former bear a family resemblance to those of the 


174 MARS AND ITS CANALS chap, xv 

earth ; the latter are peculiar to Mars, finding no coun- 
terpart upon the earth at all. 

Introduction to the mystery came about in this wise, 
and will be repeated for him who is successful in his 
search. When a fairly acute eyed observer sets himself 
to scan the telescopic disk of the planet in steady air, 
he will, after noting the dazzling contour of the white 
polar cap and the sharp outlines of the blue-green seas, 
of a sudden be made aware of a vision as of a thread 
stretched somewhere from the blue-green across the 
orange areas of the disk. Gone as quickly as it came, 
he will instinctively doubt his own eyesight, and credit 
to illusion what can so unaccountably disappear. Gaze 
as hard as he will, no power of his can recall it, when, 
with the same startling abruptness, the thing stands 
before his eyes again. Convinced, after three or four 
such showings, that the vision is real, he will still be 
left wondering what and where it was. For so short 
and sudden are its apparitions that the locating of 
it is dubiously hard. It is gone each time before he 
has got its bearings. 

By persistent watch, however, for the best instants 
of definition, backed by the knowledge of what he is 
to see. lie will find its coming more frequent, more 
certain and more detailed. At last some particularly 
propitious moment will disclose its relation to well- 
known points and its position be assured. First one 

chap, xv THE CANALS 175 

such thread and then another will make its presence 
evident ; and then he will note that each always appears 
in place. Repetition in situ will convince him that 
these strange visitants are as real as the main markings, 
and are as permanent as they. 

Such is the experience every observer of them has 
had; and success depends upon the acuteness of the 
observer's eye and upon the persistence with which he 
watches for the best moments in the steadiest air. Cer- 
tain as persistence is to be rewarded at last, the diffi- 
culty inherent in the observations is ordinarily great. 
Not everybody can see these delicate features at first 
sight, even when pointed out to them ; and to perceive 
their more minute details takes a trained as well as an 
acute eye, observing under the best conditions. When 
so viewed, however ,(the disk of the planet takes on a 
most singular appearance. It looks as if it had been 
cobwebbed all over. Suggestive of a spider's web seen 
against the grass of a spring morning, a mesh of fine 
reticulated lines overspreads it, which with attention 
proves to compass the globe from one pole to the other. 
The chief difference between it and a spider's work is 
one of size, supplemented by greater complexity, but 
both are joys of geometric beauty. For the lines are of 
individually uniform width, of exceeding tenuity, and of 
great length. These are the Martian canals/) 

Two stages in the recognition of the reality confront 

176 MARS AND ITS CANALS chap, xv 

the persevering plodder: first, the perception of the 
canals at all ; and, second, the realization of their 
very definite character. It is wholly due to lack of 
suitable conditions that the true form of the Martian 
lines is usually missed. Given the proper prerequisites 
of location or of eye, and their pencil-mark peculiarity 
stands forth unmistakably confessed. It is only where 
the seeing or the sight is at fault that the canals either 
fail to show or appear as diffuse streaks, the latter being 
a halfway revelation between the reality and their not 
being revealed at all. Much misconception exists on 
this point. It has been supposed that improved at- 
mospheric conditions simply amount to bringing the 
object nearer by permitting greater magnification with- 
out altering the hazy look of its detail. 1 Not so. They 
do much more than this. They steady the object much 
as if a page of print from being violently shaken should 
suddenly be held still. The observer would at once 
read what before had escaped him for being a blur. 
So is it with the canals. In reality, pencilings of ex- 
treme tenuity, the agitations of our own air spread them 
into diffuse streaks; an effect of which any one may 
assure himself by sufficiently rapid motion of a drawing 
in which they are depicted sharp and distinct, when he 
will sec them take on the streaky look. As the writer 
has observed them under both aspects, and has seen 
1 M. I'abb Moreux. 

chap, xv THE CANALS 177 

them pass from the indefinite to the defined as the 
seeing improved, he has had practical proof of the fact, 
and this not once, but an untold number of times. 

Atmospheric conditions far superior to what are good 
enough for most astronomic observations are needed 
for such planetary decipherment,^ and the observer 
experienced in the subject eventually learns how all- 
important this is. Under these conditions the testi- 
mony of his own eyesight upon the character of these 
markings is definite and complete. (And the first trait 
that then emerges from confusion is that the markings 
are linefy not simply lines in the sense that any suffi- 
ciently narrow and continuous marking may so be 
called, but lines in the far more precise sense in which 
geometry uses the term. (They are furthermore straight 
lines. As Schiaparelli said of them : they look to have 
been laid down by rule and compass/) The very marvel 
of the sight has been its own stumbling-block to recog- 
nition, joined to the difficulty of its detection. For not 
only is the average observatory not equipped by nature 
for the task, but what is not good air often masquerades 
as such. Trains of air waves exist at times so fine 
as to confuse this detail, or even to obliterate it entirely; 
while at the same time they leave the disk seemingly 
sharp-cut, with the result that one not well versed 
in such vagaries thinks to see well when in truth he is 
debarred from seeing at all. When study of the condi- 

178 MARS AND ITS CANALS chap, xv 

tions finally ends in putting him upon the right road, 
the sight that rewards him can hardly be too graphi- 
cally described. 

Next to the fact that they are lines, definiteness of 
direction is the chief of their characteristics to strike 
the observer. /The lines run straight throughout their 
course. This is absolutely true of ninety per cent of 
them, and practically so of the remaining ten per cent, 
since the latter curve in an equally symmetric manner^ 
Such directness has I know not what of immediate im- 
pressiveness. Quite unlike the aspect of the main 
markings, which show a natural irregularity of outline, 
these lines offer at the first glance ajno^tjmjiatliral 
regularity of look. Nothing on Earth of natural origin 
on such a scale bears them analogue. Nor does any 
other planet show the like. They are, in fact, distinc- 
tively Martian phenomena. This is the first point 
in which they differ from the markings we have hitherto 
described. The others were generic planetary features; 
these are specific ones, peculiar to Mars. 1 

1 As some misrepresentation has been made on this subject through 
misapprehension of the writer's observations on Venus and Mercury, 
it may be well to state ttiat the tenuous markings on both these other 
planets entirely lack the unnatural regularity distinguishing the 
anals of Mars. The Venusian lines arc hazy, ill-defined, and non- 
uniform; the Mercurian broken and irregular, suggesting eraeki. 
Wither resemble the Martian in marvelous precision, and have never 
born called canals by the writer nor by Schiaparelli. but solely by 
tho*e who have not seen them and have misapprehended their char- 
arter and look. 

chap, xv THE CANALS 179 

Equally striking is the uniform width of each line from 
its beginning to its end, as it stands out there upon the 
disk. The line varies not in size throughout its course 
any more than it deviates in direction.) It counterfeits 
a telegraph wire stretched from point to point. Like 
the latter seen afar, the width, too, is telegraphic. For 
it is not so much width as want of it that is evident. 
Breadth is inferable solely from the fact that the line 
is seen at all, and relative size by difference of insist- 
ency. (Indeed, the apparent breadth has been steadily 
contracting as the instrumental, atmospheric, and per- 
sonal conditions have improved) All three of the 
factors have conduced to such emaceration, but the 
middle one the most. For the air waves spread every 
marking, and the effect is relatively greatest upon those 
which are most slender. As the currents of condensa- 
tion and rarefaction pulse along, their denser and their 
thinner portions refract the rays on either side of their 
true place, and thus at the same time confuse a mark- 
ing and broaden it. {The consequence is that the better 
the atmospheric conditions and the more that has been 
learned about utilizing them, the finer the lines have 
shown themselves to be) 

Herein we have a specific intrinsic difference between 
the fundamental features and these lines: the main 
markings have extension in two dimensions, the latter 
in one. 

180 MARS AND ITS CANALS ohap. v 

I distinctive as they thus are, they have, in keeping with 
their appearance, been given a distinctive name, that of 
canal. Useful as the name is and, as we shall later see, 
applicable, it must not be supposed that what we see 
are such in any simple sense. No observer of them has 
ever considered them canals dug like the Suez Canal 
or the phcenix-like Panama one. This supposition 
is exclusively of critic creation. 

Their precise width is not precisable. They show 
no measurable breadth and their size, therefore, ad- 
mits for certain only of an outside limit. They cannot 
be wider than a determinable maximum, but they may 
be much loss than this. The sole method of estimating 
their width is by comparison of effect with a wire of 
known caliber at a known distance. For this purpose 
a telegraph wire was stretched against the sky at 
Flagstaff, and the observers, going back upon the mesa, 
observed and recorded its appearance as their stations 
grew remote. It proved surprising at what great dis- 
tances a slender wire could be made out when thus 
projected against the sky. The wire in the experiment 
was but 0.0720 of an inch in diameter and yet could be 
seen with certainty at a distance of 1800 feet, at which 
point its diameter subtended only 0.69 of a second of 
arc. How small this quantity is may be appreciated 
from its taking more than ninety such lines laid side 
by side t make a width divisible by the eye. Such 

chap, xv THE CANALS 181 

slenderness at the then distance of Mars would corre- 
spond, under the magnification commonly used, only 
to three quarters of a mile. Theoretically, then, a line 
three quarters of a mile wide there should be visible 
to us. Practically, both light and definition is lost 
in the telescope, and it would be nearer the mark to con- 
sider in such case two miles as the limit of the percep- 
tible. With the planet nearer than this, as is often the 
case, the width which could be seen would be propor- 
tionally lessened. Perhaps we shall not be far astray 
if we put one mile as the limiting width which could be 
perceived on Mars at present, with distance at its least 
and definition at its best. 

That so minute a quantity should be visible at all 
is due to the line having a sensible length and by sum- 
mation of sensations causing to rise into consciousness 
what would otherwise be lost. A stimulus too feeble 
to produce an effect upon a single retinal rod becomes 
recognizable when many in a row are similarly ex- 

The experiment furnished another criterion, of im- 
portance as regards the supposition that the lines on 
Mars are illusory. It showed that brain-begotten im- 
pressions of wires that did not exist could be told from 
the real thing when the wire subtended 0.69 of a second 
of arc or more; that below this the outside stimulus 
was too weak to differ recognizably from optic effects 


otherwise produced; while when the real wire was 
diminished to 0.59", it could not be seen at all. Now, 
the majority of lines on Mars so far recognized and 
mapped lie in strength of impression far above the 
superior limit of 0.69". To one versed in Martian canal 
delect ion there is no possibility of self-deception in the 
case, the canals being very much more salient objects 
to an expert than those who have not seen them sup- 
pose. For it must not be imagined that, when one 
knows what to be on the lookout for, they are the diffi- 
cult objects they seem to the tyro. Just as the satel- 
lites of Mars were easily seen once they were discovered, 
s< i with these lines. 

A mile or two we may take, then, with safety as the 
smallest width for one of the lines. The greatest was 
got by comparing what is by far the largest canal, the 
Nilosyrtis, with the micrometer thread. From such 
determination it appeared that this canal was from 
25 to 30 miles wide. But it is questionable whether 
the Nilosyrtis can properly be termed a canal, so 
much does it exceed the rest. It is certainly far 
larger than the majority of them. From comparative 
estimates between its size and that of the others, 15 
to 20 miles for the width of the larger of the Martian 
canals seems the most probable value, and 2 or 3 
miles only of the more diminutive of those so far 



Showing the Euraenides-Orcus. 

/On the other hand, the length of the canals is rela- 
tively enormous. With them 2000 miles is common; 
while many exceed 2500, and 
the Eumenides-Orcus is 3540 
miles )from the point where 
it leaves the Phcenix Lake 
to the point where it enters 
the Trivium Charontis. This 
means much more on Mars 
than it would on Earth, 
owing to the smaller size of 
the planet. (Such a length exceeds a third of the 
whole circumference of its globe at the equator. 
But what is still more remarkable, throughout the 
whole of the long course taken by the canal, it swerves 
neither to the right nor to the left of the great circle 
joining the two points) 

Of these several peculiarities of the individual canal 
it is difficult to know to which to allot the palm for 
oddity, great circle directness, excessive length, want 
of_width, or striking uniformity. Each is so anomal- 
ously unnatural as to have received the approving 
stamp of incredulity. Yet so much, wonderful as it is, 
is encountered on the very threshold of the subject. 



liTUCH more stands beyond. For, outdoing in 
suggestiveness the individual traits of the lines, 
is the relation shown by them to one another. It is 
the communal characteristics of the phenomenon that 
are most surprising. 

The individual peculiarities of the lines impress 
themselves at once; the communal, only as the result 
of experience, collation, and thought. As the observer 
becomes trained, the more lines he is able to make out, 
until they fairly seam the whole surface of the light 
areas of the planet. Their name collectively is legion; 
while to name them individually is fast getting, for the 
number detected, to be impossible. As with the in- 
creasing family of asteroids, figures alone will prove 
adequate to the task. 

Interdependence, not independence, marks the atti- 
tude of the canals. Each not only proceeds with abso- 
lute directness from one point to another, but at its 
terminals it meets canals which have come there with 
like forthrightnessfrom other far places upon the planet. 
Nor is it two only that thus come together at a com- 
mon junction. Three, four, five, up to as many as 


chap, xvi THEIR SYSTEM 185 

fourteen, thus make rendezvous, and it is a poor 
junction that cannot show at least six or seven; (The 
result is a network which triangulates the surface of the 
planet like a geodetic survey into polygons of all shapes 
and sizes, the Arian areolas. The size of the pieces 
forming this tesselate ground depends solely upon the 
fineness of the definition. With every increase in the 
power of seeing, each areola is cut into still smaller 
portions,} usually by connection between its corners. 
Thus a polygon or rhombus is split into triangles which 
may themselves be divided in like manner, the mosaic 
breaking into bits, the sides of which, however, always 
remain clean-cut. 

(From this arrangement it is at once evident that the 
canals are not fortuitously placed. That lines should 
thus meet exactly and in numbers at particular points, 
and only there, shows that their locating is not the out- 
come of chance.) If very thin rods be thrown hap- 
hazard over a surface, the probability that more than 
two will cross at the same point is vanishingly small. 
Increasingly assured is it that this would not happen 
generally. The result we see is therefore not a matter 
of chance x but of some law working to that end.) 

To the detection of what that law is precedes the 
easier ascertainment of what it is not. (The lines, for 
example, cannot be rivers, which was the first explana- 
tion offered of them by Proctor many years ago, be- 


cause of their peculiar straightness. Nor can they be 
channels, the name given to them by Schiaparelli, 
except in the non-committal sense in which he used the 
term. For here again their geometric regularity is bar 
to any estuary-like hypothesis. For quite another rea- 
son they cannot be cracks, because of their uniform 
size throughout. Their unbroken character is another 
fatal objection to the same suggestion) For cracks in 
ground never pursue for any great distance a continu- 
ous course, any more than they keep uniform or straight. 
The state of an old ceiling is a case in point. When it 
breaks, it does so in fissures that proceed a certain way, 
then give out to be continued by others roughly parallel 
to the first, but parted from them. The same char- 
acter is shown by the rills on the moon. The 'Straight 
Wall, ' so called, is composed of three such sections, and 
the little rill to the right of it, west of Birt, of four. 

Thus were they seen at Flagstaff, and as, to the 
writer's knowledge, they have not been so depicted 
elsewhere, the fact may serve to give some idea of the 
definition there 

That the underlying cause is not explosion or con- 
traction is also evidenced by the canals collectively 
as well as individually, their arrangement into a sys- 
tem, for cracks, however produced, could only origi- 
nate from certain centres and could not fit into those 
starting from others, as the canals invariably do. For 

chap, xvi THEIR SYSTEM 187 

each canal goes as undeviatingly to one terminal as it 
left forthrightly from another. If one wishes to see 
what explosion or contraction can do, he has only to 
look at the moon through an opera-glass, when he will 
be shown a very different sight from what the drawings 
of Mars detail. Thus just as, considered individually, 
the lines cannot be watercourses because of their 
straightness,(so they cannot be cracks because of dove- 
tailing into one another/} 

The fact that they form a system shows that what- 
ever caused them operated over the whole planet, linked 
in cause as in effect throughout each section. This at 
once negatives any purely physical cause of which we 
have cognizance. For upon a globe still so subject to 
physical vicissitude as Mars by its aspect shows itself 
to be, latitude must tell in the phenomena its zones 
exhibit. Polar snows that wax and wane speak of 
arctic conditions very diverse from temperate and 
tropic states, and what would affect the one could not 
influence the other. Yet the mesh rises superior to 
zonal solicitation as to local barrier. It is not some- 
thing dependent either on the temperament or the 
complexion of the globe's different parts. It tran- 
scends surface restriction and becomes planet-wide in its 
working. The importance of this omnipresence dilates 
in meaning as one dwells in thought upon it. 

Ubiquitous as it is, the mesh which thus covers the 

188 MARS AND ITS CANALS chap, xvi 

Martian surface like a veil spread completely over it, 
is unlike a veil in being of irregular texture. Not only 
are the interstices of various shape and pattern, but the 
mesh itself is of locally differing size. Though the 
threads are straight and uniform throughout, they are 
not all alike, besides being unsymmetrically inter- 
woven. Some are at least of ten times the coarseness 
of others, and from this fact and the bo-peep effect of 
our air waves all are not visible at once. In conse- 
quence the network is not so impressive at first glance 
as it becomes upon a synthesis of the observations. 
When this is done, the surface proves to be fairly 
evenly cut up, as recourse to the maps printed in this 
volume will amply demonstrate. These maps, as on 
page 31, are made from the results of but one opposi- 
tion, and as at each opposition some zone is in a more 
canal-showing state than others, owing to the Martian 
season at the time, a still greater uniformity in canal 
distribution results from a blending of many. 

From the completeness of the mesh, it follows that in 
the course taken severally by the canals no one direc- 
tion preponderates over another. Considered by and 
large, the canals seem to be equally distributed round 
the compass points; and this at all longitudes and 
nearly all latitudes. Tropic, temperate, and even arctic 
canals show a pleasing impartiality in the matter of 
the course pursued. The only exceptions occur in the 




neighborhood of the pole. There a slight tendency 
may be seen to a north and south settings 

Though so much is visible in a general way from the 
map, it is of interest to go into the subject with more 
particularity and to that end to show it statistically. 
The several canals traversing each zone were therefore 
counted, and the area of the zone computed. The man- 
ner of canal distribution thus found is given in the 
following table, in the second column of which stand the 
areas of the several zones upon the planet, each ten 
degrees wide, except the one next the snow, and in the 
third the number of canals found traversing them, re- 
duced to percentages of the 0-10 zone. A fourth col- 
umn shows the total length of the canals in each zone, 
those from to 20 being taken from the 1896 globe, 
those from 20 to 90 from the 1903. This is in order 
to annul the effect of the seasons upon the showing of 
the canals as much as possible. 



No. of Canals 

Actual Length 





10 -20 




20 -30 




30- 40 




40 -50 




50 -60 




60 -70 




70 -80 




80 -85 




190 MARS AND ITS CANALS chap, xvi 

The numbers continue fairly non-committal until 
we begin to approach the pole, when they commence 
to increase. Much the same result is got if we take 
the actual canal-lengths in each zone, as the fourth col- 
umn shows. (The crowding of the canals poleward is 
marked. The canals, therefore, are phenomena that 
stand in peculiar relationship to the polar cap. This 
corroborates the inference about them due to their 
running out of the edge of the snow. They not only 
emanate from it, but they do so in numbers surpassing 
what is elsewhere observable over the disk) 

Otherwise is it with their departure-points. These 
are not scattered haphazard over the surface, but bear 
to its genera] features definite relations. If we consider 
the map, obliterating the lines, and then seek to connect 
the most salient points of the planet's topography by 
direct avenues of communication, we shall find that our 
putative lines fall exactly where the real ones occur. 
For the most part, the real lines emanate from well- 
marked in. lent at ions in the dark regions, fitted by 
natural position for departure-points, what, if these 
were seas, we should call their most conspicuous bays. 
They thus leave in the southern hemisphere the deeper 
folds of the great diaphragm, for the most part ; though 
on occasion they run out of them where they will. 
Ironi equally conspicuous points in the dark northern 
areas other lines proceed; while in the centre of the 

chap, xvx THEIR SYSTEM 191 

continents, the canals make for more or less salient 
_spgts^_small patches of shading like the Trivium or the 
Wedge of Casius, or simply round black radiants, like 
the Luci Ismenii. 

From this it appears that the lines are locally de- 
pendent upon the general topography of the funda- 
mental features of the surface. For some reason they 
connect the very points most suggestive of intercom- 
munication. As from their characteristics it is per- 
fectly evident that the lines are neither rivers nor 
cracks, it follows that such a communicating habit is 
of the most telltale character. (To be so dissimilar in 
kind from the main markings and yet so dependent 
upon them, hints that their positioning occurred after 
the formation of the main features themselves. We^ 
reach thus from the look of the lines and their location 
a most striking deduction, that the lines are not coeval 
with the main markings, but have come into being later 
and with reference to the general topography of the 
planet. The network is not only a mesh de facto, then, 
but one de jure, which, subsequent to the fashioning of 
the seas and continents and what these have now be- 
come, has been superposed upon them\ 



T7U1AUGHT with more difficulty than the detection 
-*- of the lines alone is the next discovery made 
upon the disk : the recognition of pairs of lines trav- 
ersing it. 

In 1879, while Schiaparelli was engaged in scrutiniz- 
ing the strange canali he had discovered on the planet 
the opposition before, he was suddenly surprised to 
mark one of them double. Two closely parallel lines 
confronted him where but a single one had previously 
stood. So unaccountable did the sight seem ; that he 
hesitated to credit what he saw, being minded to at- 
tribute the vision to illusion of some sort and the more 
so that it was not renewed. While he was still wonder- 
ing what it meant, the planet parted company with the 
Earth, carrying its enigma with it. 

When the two bodies again drew near to one another 
in 1 882, Schiaparelli set himself to watch for a recurrence 
of the strange phenomenon. Before long it came, and 
more bewilderingly than at first; for not one canal 
alone, but a score of them now showed in duplicate, 
each presenting to his astonished gaze twin lines per- 



fectly matched and preserving throughout their dis- 
tance apart. Suspecting diplopia or some other optical 
trick, he tried various eyepieces to a test of the cause 
but to no change in the effect. The twin lines con- 
tinued visible, do what he would, insisting on their own 
reality in spite of all solicitation to merge. How cau- 
tious he was in the matter, and how unwilling at first 
to believe the evidence of his eyes, is shown by the care 
he took to guard against deception. It was not until 
he had assured himself of the reality of the phenomena 
that he believed what he had seen. 

It so chanced that my first experience of the thing 
was almost equally startling, so unexpected was it and 
so exceedingly sharp was the definition at the time. 
It was in an autumn early twilight, through air almost 
perfectly still, as the light went out of the sky and the 
markings on the planet began to come forth that the 
Phison of a sudden showed in duplicate to me, clear-cut 
upon the disk, its twin lines like the rails of a railway 
track traversing Aeria. Not more vivid do those of 
our transcontinental tracks appear as one sees them 
stretching off into the distance upon our Western 
plains. More impressive was the sight from the fact 
that I was not looking for it. It simply suddenly 
stood forth, this strange parallelism of pencil lines. 
My surprise matched the wonder of the sight. 

Since then I have witnessed it several hundred times, 

194 MARS AND ITS CANALS chap, mi 

but never with more absolute certainty than at that 
first fortunate revelation. To this distinctness is due 
the amazement it then aroused. Not simply because 
of its surpassing novelty, but for the insistence with 
which it proclaimed itself was the effect to be ascribed. 
Less well seen, doubt had robbed it of its full surprise. 
It requires as a rule steady definition for its initial 
unmistakable showing, if one would be instantly con- 
vinced. Except for such it is not usually easy to the 
unpracticed, though often discernible to the expert 
after it has once been seen. But that it is real no one 
who had had a good view of the sight could doubt; 
still less after the experience had been repeated over 
and over again. 

What appears to take place is this: /where pre- 
viously a single pencil-like line joined two well-known 
points upon the disk, twin lines, the one the replica of 
the other, stand forth in its stead. The two lines of the 
pair are but a short distance apart, are of the same size, 
of the same length, and absolutely equidistant through- 
out their course. ) It is as if a second line had in some 
way been mysteriously added to the first since the 
latter was last seen some weeks before. This in a word 
is the phenomenon, technically called the gemination 
of the canals, which has since its discovery called forth 
so much comment. It is not in reality quite as simple 
or as sudden as it seems, but this was the way in which 


the phenomenon was first seen and in which it still 
continues to be criticised. 

Self-assertive of reality, the double lines are patently 
objective to him who is fortunate enough to see them 
well. Nevertheless the great difficulty of detecting 
them, and the still greater difficulty of conceiving how 
such things can be, has led many not versed in the sub- 
ject to disbelieve and from that to attempt to explain 
the sight as illusory. Scepticism seeks self -justification ; 
what is hard of acceptance for its strangeness begetting 
hypotheses of committed error which find easy cre- 
dence for their comforting conservatism. /Several 
such have in consequence been propounded to account 
for the double canals. There is the diplopic theory 
which credits them to non-focusing; the interferential 
theory which would make them optical products of the 
telescope; and the illusion theory which would have 
them quite simply imaginary \ 

Inasmuch as in any research the assurance that a 
phenomenon is real is the first point about it to be 
established, it is a scientist's duty, not only to scan the 
phenomena with jealous care to that end, but to scru- 
tinize every theory which would seek otherwise to 
account for them the testing such being only second 
in importance to observing the things themselves. 
Accordingly I have examined each of the optical theo- 
ries that have been advanced and critically compared 

I'm; MARS AND ITS CANALS chap, xyti 

what they assert and require with the results of obser- 
vation. The outcome of this research has proved as 
negativing to any other origin for the double canals 
than reality as direct observations at the telescope are 
positive on the point. To show this I shall review 
each in its consequences, confronting it with what the 
telescope has to say on the subject ; for it is of the pith 
of the matter that the reality should be as demon- 
strable on demand as on sight. Furthermore, I shall 
do this before embarking on the general account of these 
strange things, because it is vital to any interest that 
one should be assured from the start of the truth of 
what he is to read. The preface may seem to him ab- 
struse and prosy, but it will introduce him to some curi- 
ous optical properties and will eventually enhance his 
concern by proving to him that what reads like fiction 
is all the more wonderful for being fact. 

/. The Diplopic Theory 

Diplopia is the property of seeing double with one eye; 
Surprising as it sounds it is an effect not unknown to 
students of optics, though it usually requires training 
to produce. It is possible only when the eye is not 
focused on the object, and is not always possible then) 
From my experiments its feasibility seems to depend 
upon whether the focus be beyond or before what it 
should be. If the eve be focused for a point beyond the 


object, the object is doubled, if for a point this side of 
it, the latter is simply blurred. When the double is 
formed, the amount of the separation of the two images 
is a function of the distance the focus is out. The 
greater the discrepancy, the wider apart is the ensuing 
double. Nor does the image, of a line, for example, 
stop at doubling. After a certain breadth of separation 
is reached a third line appears, bisecting the interval 
between the other two. With yet greater widening 
the third line itself splits into a pair and so the reso- 
lution goes on. In my own experiments I have gone 
so far as to suspect a fifth line. Far from being uncon- 
scious, the process of producing the phenomenon is, 
with some people, of difficult accomplishment. Mr. 
Lampland, for instance, of the Flagstaff Observatory, 
to whom we owe the first photographing of the canals, 
and who sees the doubles of Mars without difficulty, 
has hitherto found diplopic vision an impossible feat. 
Even with the most practiced diplopia is never uncon- 
scious except when the object viewed, as a micrometer 
wire, has nothing to locate it in space. Now, the di- 
plopic theory of the double canals supposes that in all 
cases the eye of the observer is thus unconsciously 
out of focus. 

To this method of their manufacture the telescopic 
phenomena prove unamenable on five counts. 

1. Focusing the eye on an object is now a reflex ac- 

198 MARS AND ITS CANALS chap, xvn 

tion, so automatic has it become; in consequence one is 
commonly directly conscious when an object is not in 
focus, always so when the object presents detail. Were 
such not the case we should never, except by chance, 
sec anything defined. Observing through a telescope, 
after a modicum of practice, differs in no respect from 
observing in everyday life. Consequently, that an 
experienced observer should not know his business 
in so primary a matter is preposterous. One may or 
may not believe that "the undevout astronomer is 
mad/' but that the perpetually unfocused one would 
be is beyond debate. 

2. Generically unlikely, the failure to focus is here 
specifically out of the question. For the observer does 
not use the canals to focus on for the simple reason that 
he cannot. Like all delicate detail, the doubles appear 
not continuously but by flashes of revelation, according 
as the atmospheric waves permit of passage undis- 
turbed. To focus on them would be next to impossible 
even were it resorted to which it never is. By the 
exponents of the theory this important fact is over- 
looked : the unforeseen showing of the canals and there- 
fore the absolute lack of complicity of the eye in the 
matter. What one focuses on is the look of the main 
markings of the disk. Now, to suppose an observer 
systematically out in his perceptions of so featureful 
a planet as that of Mars, so that he does not know when 


he sees its image sharp, implies a lack of knowledge 
of astronomic observation in the supposer. 

3. Study by the writer shows the width of a given 
double canal to be constant for a given date. Within 
the errors of perception or recording the twin lines are 
always at the same epoch the same distance apart. 
The greater the number of determinations made, the 
nearer the result approaches to this mean; and the 
greater the care used in delineation, the less each value 
departs from it. 

Now, if the thing were a matter of mistaken focusing, 
an eye could not be thus true to its own mistakes. If 
it were out in its focus by a certain amount at one time, 
it would be likely to be out by a different amount at 
another. So that by the very terms of its making a 
diplopic double would be sure to vary. Indeed, in 
laboratory experiments it is impossible to prevent it. 
For the eye rests itself automatically by change of focus, 
and if it be not consciously kept awry it reverts as near 
to the true focus as it can of its own accord. 

4. Diplopia might be a respecter of persons, but it 
certainly could not be one of canals. For a given ob- 
server it must be objectively general in its application 
to the same class of objects. Consequently, if the doub- 
ling were diplopic, all canals inclined at the same angle 
to the vertical for the tilt might affect the result 
were the eye astigmatic should be similarly affected. 

200 MARS AND ITS CANALS chap, xv.i 

Parallel canals should parallel each other's action. 
With the Martian doubles this is not the case. Of two 
canals similarly inclined the one will be double, the 
other not, at the same instant and under conditions 
that are alike. And this persistently. For gemina- 
tion is an attribute of certain canals and never of others. 
At a given season of the Martian year, some canals are 
regularly double, some invariably single. Night after 
night and presentation after presentation these idiosyn- 
crasies are preserved: the doubles, always pairs, the 
single, always alone. Nor does the strength of the line 
affeel the action. The single canals are some of them 
stronger, some of them weaker, than the doubles seen 
at the same time. 

5. If of diplopic origin the mean width of all the 
doubles should be the same. For though the diplopic 
width would vary for a given canal according to the 
moment, a sufficient number of views would yield a 
mean width which would be the same for all. Tilt 
apart, the mean width of one canal would be that of 
another. Among Martian doubles, on the contrary, 
I have found the width to be a specific property 
of the particular canal. Each has its own mean width 
regardless of inclination, and this individual width 
differs as between one and another by as much as five 
to two, or. if we consider such canals as the Nilokeras 
I and II. bv more than ten to two. 


Any one of these five points is fatal to the theory; 
a fortiori all. 

//. The Interference Theory 

From the wave propagation of light it follows that 
the image of a bright line made by a lens is not itself 
a simple bright line but a bright band flanked by alter- 
nate dark and bright ones. It has, therefore, been sug- 
gested that a bright medial line is here concerned and 
that the double canal is the first of its dark pair of out- 
riders. But the suggestion does not bear scrutiny. 

1. It presupposes a central streak brighter than the 
rest of the disk to give birth to the twin dark lines. 
This should itself be visible in the image ; but no such 
bright backbone is seen. 

2. It demands a perfectly definite width of separation 
for a given aperture which is not that observed. 

3. It makes the width a function of the aperture, 
decreasing as this increases which is not sustained 
by observation. Different apertures produce no effect 
on the widths of the Martian doubles, as the writer has 
shown (Lowell Observatory Bulletin, No. 5) by a change 
of aperture from twenty-four to six inches. 

4. Under like optical conditions the optically pro- 
duced doubles would be all of a width ; while the Mar- 
tian ones show idiosyncratic widths, each peculiar to 

:>02 MARS AND ITS CANALS chap, xvn 

///. The Illusion Theory 

Known also as the Small Boy Theory from the in- 
genuous simplicity on which it rests, this theory attacks 
the reality of the doubles by questioning that of the 
canals en bloc. Because some boys from the Green- 
wich (Reform or) Charity School, set to copy a canal- 
expurgated picture of the planet, themselves supplied 
the lines which had preceptorily been left out, the 
Martian canals have been denied existence; which is 
like saying that because a man may see stars without 
scanning the heavens, therefore those in the sky do not 
exist. As to the instructions the boys received we are 
left in the dark. It looks as if some leading questions 
had unconsciously been put to them. At all events, 
English charity boys would seem to be particularly 
pliant to such imagination, for when Flammarion re- 
tried the experiment with French schoolboys, and even 
inserted spaced dots for the canals in the copy, not a 
boy of them drew an illusory line. 

The fact is, this is one of those deceptive half-truths 
which is so much more deleterious than an unmitigated 
mistake. Under certain circumstances it is quite pos- 
sible to perceive illusory lines, due either to shadings 
otherwise unmarked and thus synthesized or to im- 
mediately precedent retinal impressions transferred 
to i .laces where they do not belong by rapid motion 


of the eye, as I had myself discovered before the 
English experiment had been tried. But, as I have 
also found out, these effects are produced only at the 
limit of vision, and in that limbo of uncertainty the 
whole art of the observer consists in learning to dis- 
tinguish the true from the false. Strength of impres- 
sion, renewed effect in situ, and a peculiar sense of 
reality or the reverse enable him to adjudge the two. 
More experience than the boys possessed would have 
helped them to part the sheep from the goats. But, 
furthermore, and fatally to the theory here in question, 
the Martian canals when well seen are not at the limit 
of vision as its framers supposed, but well within that 
boundary of doubt ; so that the premise upon which the 
whole theory rests gives way. Under good atmospheric 
conditions the canals are comparable for conspicuous- 
ness to many of the well-recognized Fraunhofer lines 
and are just as certainly there. 

(irhus each attempt to prove the doubles non- 
objective turns out when specifically examined to be in- 
consistent with the facts. With the assurance of their 
reality thus made doubly sure, we pass to consideration 
of the things themselves^ 




DIGHTLY viewed, no more subtle tribute could be 
paid to the remarkable character of the phenom- 
enon of gemination than the scepticism with which it 
was immediately received and which it still continues 
to elicit . That the sight should be regarded as illusory 
speaks for its surpassing strangeness; and so far as 
oddity goes the encomium is certainly deserved. Of 
the bizarre features of this curiously marked disk, 
the double canals were at the time of their discovery 
the culmination, and though things stranger still if 
possible have since been seen there, it is not wonderful 
that doubt should still incredulously stare. If the mere 
account of them reads like romance, to see them is an 

Nothing astronomical that I have ever seen has been 
so startlingly impressive as my first view of a double 
canal. Even in narration the thing justifies its effect. 
For m double canal consists of a pair of twin dark fila- 
ments, perfectly parallel throughout their course and 
inclosing between them ground of the same ochreish 


chap, xviii THE DOUBLE CANALS 205 

cast as that which lies without. Only on occasion is 
this tint of their midway departed from, and then only 
toward a darkening, never toward a lightening of it. 
Except for appearing paired, the lines resemble pre- 
cisely the usual single canals. In length they vary 
from a few hundred to a few thousand miles, while in 
width each component, for narrowness, hardly permits 
of definite ascription^ 

Compared for strength with the usual canal the lines 
of a double seem to hold on the average an intermediate 
position between the larger and the smaller of the single 
canals so far detected. Owing, however, to the massed 
effect of the pair by reason of their closeness, they have 
an advantage in showing over the singles of two to one. 
And this renders them among the most conspicuous and 
important meshes of the canal network. 

Like the single canals, they vary in strength with the 
Martian time of year; at certain seasons developing 
into heavy pencil lines and at others fading away to the 
merest gossamers, only just discernible like cobwebs 
stretched across the face of the planet.) 

Although the individual constituent lines vary in 
aspect and never rise at their most to cognizable 
breadth, the distance parting their centres, or the width 
of the double, is quite measurable. The only difficulty 
in the way of its determination lies in the absence of a 
procurable unit small enough to mete it. The usual 

206 MARS AND ITS CANALS chap, xvm 

spa' j-\v 

parison with these filaments and present a standard 
only analogic at best. Nevertheless, '.." means of the 
finest threads that could be got, estimates of the dis- 
tance between the pairs were made at Flagstaff in 1905, 
and the results agree as closely as the means permit 
with those got by measurement of the doubles as 
depicted in the drawings. 

Of what they look like, the following illustrations 
give a fair idea, only that instead of being more geo- 
metrically regular in the 
drawing than in reality the 
fact is the other way. Free- 
hand draftsmanship at the 
telescope is incapable of ren- 
dering their ruled effect. No 
railway metals could be laid 
down with more precision. 
As to their size, the following 
figures derived from a typical double canal, the Phison, 
give some conception. This great artery of inter- 
communication between the Sabaeus Sinus and the 
Nilosyrtis is, roughly speaking, 2250 miles long; the 
distance between the centres of the two constituents 
is about 130 miles, and each line is perhaps 20 miles 
in breadth, when at its maximum strength. The 
pair follow, apparently, the arc of a great circle from 




Martian doubles (corroborating 
the above). 

the Portus Sigaeus on the Mare Icarium to the Pseboas 
Lucus in latitude 40 north. The Portus Sigaeus con- 
sists of two little nicks in the coastline, looking like 
the carets one makes in 
checking off items down a 
list, if the space between 
the down and up strokes 
were then filled in; the 
Pseboas Lucus, on the other 
hand, is a large round dot 
like a small ink spot. To 
these two differently appear- 
ing spots, the twin lines of 
the Phison behave differently. While each line leaves 
centrally its own caret of the Portus Sigaeus at the 
south, at the north each touches peripherally the 
Pseboas Lucus, on the east and west sides respectively, 
the two thus just holding the Lucus between them. 
In position the lines are invariable, though in visibility 
not. Sometimes only one is seen, sometimes both show 
faintly, and sometimes both are conspicuously strong. 
The delicacy of the observations by which this detail 
was established is second only to its importance. It 
destroys at a stroke all possibility of diplopic un- 
reality, since were that the fact the Pseboas Lucus 
should be doubled, which it is not. At the same time 
it opens vistas into the true construction of the 

208 MARS AND ITS CANALS chap, xvm 

things themselves, at present more suggestive than 

In the greal circle character of its course the Phison 
is quite normal. The majority of the double canals 
pursue the like method, running straight over the 
surface from one point to another, the constituents 
remaining equidistant throughout. -But such forth- 
rightness of direction, though the rule, is not with- 
out exceptions. The Thoth-Nepenthes, for example, 
sweeps round in a seemingly continuous curve to the 
west -southwest from the Aquae Calidae to the Lucus 
Moeris like some mighty bow perpetually bent. Never- 
theless its lines are no less careful for all their curving 
to keep their distance from one end to the other of their 
course. The quality of being paired rises superior to 
change of direction. 


Now. the first point to be noticed about the doubles 
is that bilateralism, or the quality of being double, 
is not a universal trait of the canals, either actually or 
potentially ; it is not even a general one. Out of the 
four hundred canals seen at Flagstaff, only fifty-one 
have .it any time displayed the quality; that is, one 
eighth roughly of the whole number observed. This 
point is most important; for the fact is of itself enough 
to disprove any optical origin for the phenomenon. 
The characteristic of doubling so confidently ascribed 

chap, xviii THE DOUBLE CANALS 209 

by those who have not seen it to general optical or ocular 
principles proves thus the exception, not the rule, with 
the canals, and by so doing disowns the applicability 
of any merely optical solution. We shall encounter 
many more equally prohibitive bars to illusory expla- 
nation before we have done with the doubles, but it is 
interesting to meet one in this manner at the very 
threshold of the subject. 

On the other hand, the characteristic when possessed 
is persistent in the particular canal, in posse if not in esse. 
Once shown by a canal, that canal may confidently 
be looked to at a proper time to disclose it again. 
In short, bilateralism, or the state of being dual, is an 
inherent attribute of the individual canal, as idiosyn- 
cratic to it as position and size^) 

The catalogue of canals possessing this property, 
so far as they have been detected at Flagstaff to date, 
number fifty-one if we include in the list wide parallels 
like the Nilokeras I and II. Eight of these were ob- 
served in 1894 ; nineteen more were added in 1896, 
making twenty-seven; in 1901 the total was raised to 
thirty ; in 1903 to forty-eight ; and in 1905 to fifty-one. 
Arranged by years they are tabulated below, where the 
numeral to the left registers for each its first recording 
and the position held by it in the list. The starred 
canals much exceed the others in width, and possibly 
denote a different phenomenon. 

210 MARS AN] 

) IT 



Date Confused 





1. Ganges 



2. Nectar 



3. Euphrates 


Cerberus S. 

4. *XiIokeras I 



and II 

Cerberus N. 


5. Phison 



6. Asopus 


7. Jamuna 



8. Typhon 




. Djihoun 

Ganges Typhon 


Kuphrates Avernus S. 




9. Lethes 





10. Dis S. 



11. Titan 


12. Laestrygon 


13. Tartarus 



14. Cocytus 


1."). Sitae us 



16. Amenthes 



17. Adamas 


18. ( <rberus N. 


19. Cerberua S. 



*Nilokeras I 

21. Gelbes 

and II 

22. Erebus 


23. Avernus N. 


24. (iigas 



25. A lander 



20. Gihon 


27. Hiddekel 








Date Confused 



35. Astaboras S. 


36. Nar 


37. Chaos 

Astaboras S. 

38. Aethiops 

Adam as 

39. Hyblaeus 


40. Eunostos 

Cerberus S. 

41. Thoth 

Cerberus N. 

42. Nepenthes 


43. Triton 


. *Propontis 

44. Pyramus 


45. Fretum Anian 


46. Vexillum 




Cerberus S. 


47. Nilokeras I 


. Polyphemus 

Cerberus N. 


48. Tithonius 




















[n spite of possessing the property of pairing, a canal 
may not always exhibit it. To the production of the 
phenomenon the proper time is as essential as the 
property itself. So far as a primary scanning or first 
approximation is capable of revealing, a canal will be 
single at one Martian season and double at another. 

212 MARS AND ITS CANALS chap, xnn 

Thus these canals alternated in their state to Schia- 
parelli and for the earlier of his own observed oppo- 
sitions to the writer. In consequence Schiaparelli 
deemed gemination a process which the canal periodi- 
cally underwent. Three stages in the development 
were to him distinguishable : the single aspect, a short 
confused aspect, and the clearly dual one.; 

In the single state the canal remained most of the 
time. It then underwent a chrysalid stage of confu- 
sion to emerge of a sudden into a perfect pair. Fur- 
thermore, he noted the times at which the pairing took 
place, to the formulating of a law in the case de- 
rived from the observations of more than one opposition. 
His law was that the gemination occurred, on the aver- 
age, three months (ours) after the summer solstice 
of the northern hemisphere, lasted four to five months, 
then faded out to begin afresh one month after the vernal 
equinox of the same hemisphere and continue for four 
months more. Expressed in Martian seasonal chro- 
nology, the periods would be about half as long. At 
certain times then the most pronounced specimens of 
doubles showed obstinately single, while the periodic 
metamorphosis that transformed them into duplicates 
was timed to the changes of the planet's year. Gemi- 
nation, then, was a seasonal phenomenon. 

Advance in our knowledge of the phenomenon since 
Schiaparelli's time, while still showing the thing to be 

chap, xvm THE DOUBLE CANALS 213 

of seasonal habit, has changed our conception of it. 
It now appears that in some cases certainly, and pos- 
sibly in all, the dual aspect is not a temporary condition, 
but the differing pronouncement of a permanent state, 
the fact of gemination so called being confined to a 
filling out of what is always skeletonly there. As the 
canals have come to be better seen, the three stages of 
existence have in some cases become recognizable as 
only different degrees in discernment of an essential 
double condition; the single appearance being due to 
the relative feebleness of one of the constituents and the 
confused showing to the weakness of both, which are 
then the more easily blurred by the air waves} In cer- 
tain canals the last few oppositions, 1901, 1903, and 
1905, have disclosed this unmistakably to be the case, 
as with the Phison and Euphrates, for example. /With 
them the double character has been continuously visible, 
appearing not only when by Schiaparelli's law it should, 
but at the times when it should not ; only on these latter 
occasions it was harder to see, whence the reason it was 
previously missed. So that further scrutiny, while in 
no sense discrediting the earlier observations, has ex- 
tended to them some modification, and disclosed the 
underlying truth to be the varying visibility, the thing 
itself, except for strength in part or whole, persisting 
the same^ Improvement in definition has lowered the 
see-level to revelation of continuous presence of the 


dual state. It is only on occasion that the improvement 
is sufficient for the thing when at its feeblest to loom 
thus above the horizon of certainty; yet at such mo- 
ments of a rise in the seeing it is enough to allow it 
to be glimpsed. Thus it fared with the Adamas at the 
opposition of 1903, with the Gigas, and with many 
another in years gone by. Separation has come with 
training and generally in the case of the wider doubles, 
which leads one to infer that ease of resolution is largely 
responsible for assurance of the permanency of the dual 
state. Perplexing exceptions, however, remain, so 
that it is possible at present only to predicate the 
principal of most of the double canals but not of all. 
Leaving the exceptions out of account for the moment, 
we pass to those general characteristics which are in- 
timately linked with what has just been said. 

Inasmuch as the act of getting into a state antedates 
the fact of being there, it is logical to let the description 
of the first precede. An account of the process of gemi- 
nation may thus suitably come before that of its result. 

Mux. affecting the double canals in whole or part, 
is the cause of the apparent gemination. Recording 
as the flux is partitive or total is a single or a dual state 
produced. At the depth of its inconspicuousness the 
canal may cease to be visible at all; this occurs when 
both lines fade out. On the other hand, the one line 
may out fade the other, and we are presented with a 

chap, xviii THE DOUBLE CANALS 215 

seemingly single canal, at this its minimum showing. 
In such seasons of debility the one line may appear and 
the other not, or occasionally the other show and the one 
not, according to the air waves of the moment. It is 
at these times that the double simulates a single canal, 
and unless well seen and carefully watched might easily 
masquerade successfully as such^> The Hiddekel in the 
depth of its dead season is peculiarly given to this al- 
ternately partitive presentation. (A,s the flux comes on, 
one or both lines feel it. If one only we are likely to 
have a confused canal ; if both, a difficult double. The 
strength of the lines increases until at last both attain 
their maximum, and the canal stands revealed an un- 
mistakable pair, the two lines paralleling one another 
in appearance as in position) 

(At the canal's maximum and minimum the equality 
of its two constituents is chiefly to be remarked, though 
it occurs on other occasions as well. But, what is signifi- 
cant, when the two differ it is always the same one that 
outdoes its fellow) It may be the right-hand twin in 
one pair, the left-hand one in another; but whichever 
it be, for the particular canal its preeminence is in- 
variable. It is this canal which, except for adventitious 
help or hindrance from the air-waves, alone shows 
when the double assumes the seemingly single state. 
/We may therefore call it the original canal, the other 
being dubbed the duplicate*. In some cases it has been 



( hap xvnr 

possible to decide which is which. It might seem at 
first sight as if this point should always be ascertainable. 
But the determination is more dilemmic than appears, 
not from any difficulty in seeing the canal, but from the 
absence of distinguishing earmark at its end. In a 
long stretch of commonplace coast, the precise point of 
embouchure of a solitary canal cannot be so certainly 
fixed as to be decisive later between two which show 
close together in the same locality. It is only where 
sonic landmark points the canal's terminal that the 
problem admits of definite solution. This telltale 
tag may be a bay like the Margaritifer Sinus, or double 
gulfs like the Sabaeus Sinus, or portions of a marking 
not too large to permit of partitive location like the 
Mare Acidalium, or a canal connection like the Tacazze 
which prolongs the one line and not the other. In these 
and similar instances the two lines become capable of 
identification, and in such manner have been found 
those comprised in the following list: 

Double Canal 

Original Line 

Date of 



The Eastern 



The Western 



The Western 



The Eastern 


( lihon 

The Western 



The Northwestern 

IS' 111 

I tjihoun 

The Western 



The Eastern 


Nilokeras I and II 

The Northern 



The Southern 


J am una 

The Eastern 


( ranges 

The Western 

1 !().-, 

chap, xviii THE DOUBLE CANALS 217 

In this list of originals the canals stand chrono- 
logically marshaled according to date of detection. 
The Phison and Euphrates were the first to permit of 
intertwin identification in 1894, while the Jamuna and 
Ganges were the last to be added to the column in 1905. 
The list is not long, though the time taken to compile it 
was. In the case of the Ganges and the Jamuna, for 
example, although suspected for some time on theo- 
retic grounds, it was only at the opposition just passed 
that the fact was observationally established. In 
his Memoria V, Schiaparelli has a list of similar detec- 
tion, and if the present list be compared with his, the 
two having been independently made, the concordance 
of the result will prove striking, corroborative as it is 
of both. For the necessary observations are very 

Having thus realized the original by means of its 
superior showing, and then identified it by its position, 
it is suggestive to discover that the duplicate betrays 
its subordinate character, not only by its relative insig- 
nificance, but by its secondary position as well. The 
original always takes its departure from some well- 
marked bay, seemingly designated by nature as a de- 
parture-point, or from a caret belonging clearly to itself ; 
the adjunct, on the other hand, leaves from some neigh- 
boring undistinguished spot, as in the case of the addi- 
tional Djihoun, or makes use of a neighbor's caret, as in 

218 MARS AND ITS CANALS ohap. xrm 

the case of the second Phison and the supplementary 
Euphrates. In either case it plays something of the 
part of an afterthought; and yet the postscript when 
finished reads as an integral part of the letter. An 
example will serve to make the connection evident while 
leaving the character of the connection as cryptic as 

In the long stretch of Aerial coastline bounding the 
Marc Ecarium, which sweeps with the curve of a fore- 
time beach from the Hammonis Cornu to the tip of 
the Edom Promontory, there stand halfway down its 
far-away seeming sea-front two little nicks or indenta- 
tions. Even in poor seeing they serve to darken this 
part of the coast while in good definition they come out 
as miniature caret-like bays. They are the Portus 
Sigaei, and mark the spots where the Phison and the 
Euphrates respectively leave the coast. About four 
degrees apart, the eastern makes embouchure to the 
original Phison, the western to the original Euphrates, 
and each in some mysterious manner is associated not 
only in position but in action with the canal itself. 
In the single state each canal leaves the Mare from 
this its own caret, the Phison proceeding thence north- 
cast down the disk, the Euphrates nearly due north, 
so that starting four degrees apart at the south they 
are forty degrees asunder at their northern termini. 
Clearly ;it these latter points they are not even neigh- 

chap, xviii THE DOUBLE CANALS 219 

bors, and except for the accident of close approach at 
their other ends have nothing in common anywhere. 
And yet wiien gemination takes place a curious thing 
occurs: each borrows its neighbor's terminal as de- 
parture-point for its own duplicate canal. Having thus 
got its base the replica proceeds to parallel its own 
original canal without the least reference to the other 
canal whose own caret it has so cuckoo-wise appro- 
priated. What 
the Phison thus 
does to the Eu- 
phrates, the Eu- 
phrates returns 
the compliment 
by doing to the 
Phison. In this 
manner is produced an interrelation which suggests, 
without necessarily being, an original community of 
interest ; suggests it on its face and yet appears to be 
rather of the nature of an adaptation to subsequent 
purposes of a something aboriginally there. 

That such latter-day appropriation is the fact is 
clearly hinted by the behavior of another understudy 
of an original canal, in this case the duplicate of the 
Djihoun, which in consequence of the position of its 
original finds no neighboring embouchure already 
convenient to its use. The single or original Djihoun 

220 MA US AND ITS CANALS chap. xvn. 

Kavcs the tip of the needle-pointed Margaritifer Sinus, 
which serves a like end to the Oxus and the Indus, both 
single canals. The Sinus is itself a single bay, and so 
large that for many degrees its shores on both sides con- 
verge smoothly to their sharp apex. Because of this 
probably, the coast in the immediate neighborhood is 
without canal connection, no canal being known along 
either side till one reaches the Hydraotes at the Aroma- 
ticum Promontorium, which marks the western limit 
of the gulf. The consequence is that when the Dji- 
lioun doubles, the duplicate canal, not having any ter- 
minus ready to its hand, has to make one for itself 
by simply running into the Margaritifer Sinus, some 
distance up its eastern side. It thus advertises its ad- 
junct ival character, and at the same time the general 
fact that a neighbor's terminus, though used from prefer- 
ence, when convenient, is not an essential in the process. 
Gemination occurs of its own initiative, but is condi- 
tioned by convenience. 

Whether one canal shows thus to the exclusion of the 
other, or whether both stand so confused as not to be 
told apart, the fact remains that the double is not always 
recognizable as such. If we turn to the list of the 
doubles on page 222, we shall note that the same canals 
were not always seen in the dual condition at successive 
oppositions. Some, indeed, are so emphatically of the 
habit as to appear year after year in a paired state, but 

chap, xvm THE DOUBLE CANALS 221 

others are not so constant to their possibilities. Now, 
when it is remembered that at different oppositions we 
view Mars at diverse seasons of its tropical year, we see 
that this means that the phenomenon is seasonal; 
and furthermore that its exhibition depends upon the 
canal's position. Gemination, like the showing or non- 
showing of the single canal, is conditioned by the place 
of the canal upon the planetA 


Turning from such generic characteristics to more 
specific traits, the first thing to strike an attentive ob- 
server is that the doubles differ in width ; that they are 
not mensurably alike in the property they hold in com- 
mon of being paired. In some the twin lines are ob- 
viously farther apart than in others, and the relation 
persists however repeated the observations. Of two 
doubles the one will always surpass its fellow. This 
contrasted individuality first struck me in the Phison 
and the Euphrates; and from the first moment at 
which these doubles showed as such. The Phison pair 
seemed perceptibly the narrower of the two. A like 
distinction was evident at the next opposition and 
the next; in fact, at every succeeding one to the 
present day. Nor was the recognition of the fact 
confined to me. If we turn to Schiaparelli's Memoriae 
we shall find that that master had registered the same 



(II VI". \\ III 

idiomatic width for the two canals from first to last 
throughout his long series of records. The observation 
thus made proved to apply to each and all of these 
curious twins. 

Diversity in width for different doubles appears 
plainly in drawings where more than one double is 
depicted. As an example, two drawings are here 
given in the text, made, the one on July 13, 1905, X15, 
and the other on July 20, X313. In them the Phison, 
Euphrates, Djihoun, and Thoth appear contrasted as 
unmistakably as either of them does with the single 
canals apparent at the same time. That this drawing 
is typical is borne out by all the best measures of the 
several doubles as seen at successive oppositions, and 
marshaled in the subjoined list. How truly individual 
the quality is stands proved by the relative values in 
different years which are even more accordant than the 
absolute ones. 

The canals were : 





1. Phison 

2. Euphrates 




4 1 

3. *Protonilii8 

1. Deuteronilua 


* Poor. 








5. Pierius .... 

6. Callirrhoe . . . 

7. *Hiddekel . . . 

8. *Gihon .... 

9. Djihoun . . . 

10. Sitacus .... 

11. Jamuna. . . . 

12. Ganges .... 

13. Nilokeras I and II 

14. Nilokeras I . . 

15. Gigas .... 

16. Laestrygon . . 

17. Cerberus N. . . 

18. Cerberus S. . . 

19. Cyclops .... 

20. Nar 

21. Fretum Anian 

22. Aethiops . . . 

23. Eunostos . . . 

24. Lethes .... 

25. Marsias .... 

26. Hyblaeus . . . 

27. Amenthes . . . 

28. Thoth . . . . 

29. Nepenthes . . . 

30. Triton .... 

31. Pyramus . . . 

32. Astaboras S. . . 

33. Tithonius . . . 

34. Vexillum . . . 

35. Tartarus . . . 








* Poor. 

224 MARS AND ITS CANALS chap, xvm 

Here we have widths ranging from eleven degrees to 
two. The widths given are those when the canal was at 
or sufficiently near its full strength, and are measured 
from the centres of the constituents. We notice two 
points: the agreement of the same canal with itself 
and its systematic disagreement with others. But 
what is especially to the point, if we compare the values 
found at successive oppositions, we find that for differ- 
ent canals the values agree in their difference. This 
shows that each of these values is, in most cases if not 
in all, a norm for that particular canal; a value dis- 
tinctive of it and to which it either absolutely or rela- 
tively conforms. /In other words, the width of the 
gemination is a personal peculiarity of the particular 
canal, as much an idiosyncrasy of it as its position on 
the planet. 

Two general classes may be distinguished; those up 
t<> about five degrees in width apart and those above 
this figure. Whether such very widely separated lines 
as go to make up the second class, such as the Nilokeras 
I and II, constitutes a double is a debatable point. 
Schiaparelli thoughl they did, and so classed them. 
To me it did not at first occur so to consider them, 
and in some instances, such as the Helicon I and 
II, later observations seem to justify the omission. 
With the Nilokeras I and TI the outcome seems the 
other way. The reasons for distrust of a physical rela- 

chap, xviii THE DOUBLE CANALS 225 

tion between the constituents is not so much the dis- 
tance separating them, nor any lack of parallelism, as 
the self-sufficient manner in which they show alone. 
Even this, however, tends to be recognized in the nar- 
rower pairs as they come to be better seen. It may 
be that width alone is wholly competent to selective 
showing. For the farther apart two lines are on the 
planet, the more opportunity is afforded the air waves 
to disclose the one without the other, a relative revela- 
tion which is constantly happening to detail in different 
parts of the disk. As long as any doubt exists of a 
physical community of interest, it seems best to dis- 
tinguish such possibly merely parallel canals by suffixed 

Of this class of doubles is the Nilokeras I and II. 
So wide is it that Mr. Lampland succeeded in photo- 
graphing it as such, the two constituents showing well 
separated, and if it prove a true double it will be the 
first Martian double to leave its impress on a sensitive 
plate. Although separated by four hundred miles of 
territory, the two lines are parallel so far as observa- 
tion can detect, which, of course, is not so very easy 
with the lines so far apart. In the country between 
one crosswise canal certainly lies, the Phryxus, and 
much shading thus far unaccounted for. Recent dis- 
coveries, however, point to the cause of such shading as 
lines imperfectly seen. For in some cases the lines 


226 MARS AND ITS CANALS chap, xvm 

have actually disclosed themselves, and warrant us in 
believing that it is only imperfect seeing that keeps the 
( >t hers hid. Of the pair the Nilokeras I is itself double, 
curiously reproducing what sometimes is seen in the 
case of double stars, one of whose components turns 
out to be itself a binary. The second line of the Niloke- 
ras I lies close to its primary on the north, and was on 
the only occasion of its detection the merest of gossa- 
mers, while the Nilokeras I itself stood out strong and 
dark. Thus do these Martian details increase and mul- 
tiply in intricacy the better the seeing brings them out. 

In the case of the other doubles, the doubles proper 
so to speak, there is every indication of a physical bond 
between the pair. What that bond may be is another 
matter and seems to be of different divulging, according 
to the particular instance. At one end of the subject, 
both as the widest of these doubles and one of the most 
important, stands the Ganges. The components of 
the canal are 5.l apart. This great width, joined to 
the fact of scant extension, gives the canal a stocky 
aspect, its breadth being but one sixth of its length. 
Its width draws attention to it while the phenomena 
it exhibits intrigue curiosity. 

As early as the first opposition of my observations 
in 1894, the canal, as it underwent the process of 
doubling, showed phases of peculiarity. It was first 
caught by me as a double over toward the terminator, 

chap, xviii THE DOUBLE CANALS 227 

or fading edge of the disk ; then as it was brought nearer 
the centre by the gaining upon the longitudes, showed 
as a broad swath of shading of a width apparently equal 
to any it later exhibited. In this appearance it con- 
tinued for some months, and then in October began to 
show a clarification toward the centre. Once started, 
the lightening of its midway advanced till at last, on 
November 13, it stood out an unmistakable double, the 
two lines standing where the edges of the swath had 
previously been. Had the observations here been all 
that one could wish, the method of gemination would 
have been certain and of great interest. Unfortunately, 
the observations left much to be desired, and those re- 
peated in 1896-1897 and 1901 were of like doubtful- 
ness. A period of swarthy confusion preceded the 
plainly dual state, but whether the double simply 
clarified or widened as well it was not possible to assure 
one's self. That the canal exhibited plainly the effects 
of seasonal development was as unmistakable as the 
steps themselves were open to ambiguity. In 1903 
the canal was at its minimum and hardly to be made 
out. It seemed then, to show an actual change in 
width coincident with alteration of visibility. But 
this, too, could not be predicated with certainty. It 
was also surmisable that the westernmost line was 
the one from which the development proceeded. 

In 1905 much more was made out about it, training 

228 MARS AND ITS CANALS chap, xnu 

in the subject and increased proximity of the planet 
contributing to the result. It now became clear to 
me that the canal did develop from the western side; 

for the western edge made 
a dark line of definite bound- 
ary from which shading pro- 
ceeded to the eastern side, 
where it faded almost imper- 
ceptibly off with no defined 
line to mark its limit. That 
this shading gradually dark- 

Peculiar development of the 

Ganges. ened was evident, but 

when it could be seen at all it extended to the ex- 
treme limit of the eventual double, restricted the 
character if not the fact of an actual widening. At 
this opposition, too, the canal passed through its 
period of minimum visibility and was then seen, 
whenever it could be caught, as a confused swath of 
full width. In the case of this canal, then, a widen- 
ing in the sense of a bodily separation of two lines 
seems inadmissible. On the other hand, the gradual 
darkening of the swath, and especially the advance of 
the darkening from the western side, points to an 
interesting process there taking place. 

At the opposite^ end of the series stands the Djihoun. 
As the flanges is the widest of the instantly impressive 
doubles, so the Djihoun is the narrowest the eye has so 

chap, xvm THE DOUBLE CANALS 229 

far been able to make out. Only two fifths of the 
width of the Ganges pair, this slender double is very 
nearly at the limit of resolvability. So well propor- 
tioned are its lines to the 
space between them, how- 
ever, that in ease of recogni- 
tion it surpasses many wider 
pairs. In form, too, it is dis- 
tinctive, turning by a grace- 
ful curve the trend of the 
Margaritifer Sinus into the 

LUCUS IsmeniuS. With its Djihoun, the narrowest double. 

fundamental branch the northern of the two it 
joins what is evidently the main line of the Proto- 
nilus also the northern one to the Margaritifer 
Sinus's tip. 

It differs from the Ganges in some other important 
particulars besides width. In its case no band of shad- 
ing distinguishes it at any time. It has always been 
two lines whenever it has been seen other than as a 
single penciling; the only confusion about it being 
evidently our own atmosphere's affair. These two 
lines, furthermore, have showed, within the errors of 
observation, always the same distance apart. So that 
not only no change of intercommunication between the 
lines but no change in their places apparently occurs. 

Between these extremes in width, two hundred miles 

230 MARS AND ITS CANALS chap, xvm 

more or loss for the Ganges and seventy-five miles for 
the Djihoun, the distance parting the pairs of most of 
the double canals lies. From 3 to 3.2 on the planet 
may be taken as that of the average; the degrees denot- 
ing latitudinal ones on the surface of Mars, the length 
of which is equal to thirty-seven of our English statute 

Most of the canals conform apparently to the type 
of the Djihoun rather than to that of the Ganges. 
C areful consideration of them fails to find any increase 
or decrease of distance, between the pairs of the same 
canal at different times, which cannot be referred to 
errors inevitable to observation of such minute detail. 
In short, the double is made by the addition of a sec- 
ond line in a particular position and not by a growth 
out to it of a line coincident to begin witn with the first. 

I have said that the average width between the two 
lines of the doubles was about 3. It must not be 
supposed that this average width denotes anything 
more than an average; or, in other words, that it de- 
notes anything in the nature of a norm. The remark 
is important in view of a suggestion which I have heard 
made that we have here a system based on fundamental 
Martian units, in which, or in multiples of which, the 
dimensions of the canals are implicitly expressed. Such, 
however, does not seem to be the case. In some in- 
stances, indeed, we have certain evidence to the con- 

chap, xviii THE DOUBLE CANALS 231 

trary and that the width of the double is conditioned 
solely by antecedent place. The Phison and Euphrates 
offer a case in point. These two important arteries 
in duplicate leave, as we saw, from two carets in the 
Mare Icarium, the Portus Sigaei, held in common ten- 
ancy by both. Each pair then proceeds down the disk 
inclined at its own particular angle to the meridian in 
order to reach by a great circle course a certain spot; 
the Pseboas Lucus in one case, the Luci Ismenii in the 
other. As one of these angles is thirty-five degrees 
while the other is only three, they must, from the 
circumstances of their setting out, have not only 
different widths, but widths determinately different in 
advance, since each is, roughly speaking, foreshortened 
by the degree of divergence from the meridian. The 
one, therefore, must be about four degrees to the other's 
something less than three and a half. This is what they 
actually are as determined by measurement from obser- 
vation. That the calculated value agrees with that 
found from observation helps certify to a community 
of starting-points, but it completely does away with 
comprehensive design in the question of their widths. 
For if the one were so settled, the other could not be. 
Indeed, the next example seems to deny it to 
both. This example occurs, too, not far away from 
the scene of the first, in the twin bays of the Sabaeus 
Sinus, from which depart, mutatis mutandis, the 

l , :.l ) MARS AND ITS CANALS chap, xvm 

double Hiddekel and the two Gihon. These twin 
gulfs bear so little imprint of being other than natural 
formations, that they have been universally and very 
likely quite rightly taken for such ever since Dawes 

discovered them in 1859, long 
before things like canals were 
dreamed of. It is strange 
that when the Hiddekel and 
the Gihon were found by me 
to be double in 1897, with a 
branch of both leading from 
each bay, the connection be- 

The Sabaeus Sinus, embouchure . .. ,, , 

for the double Hiddekel aud tween the sceptically scouted 
(iillon doubles and the thoroughly 

believed-in bays should have been apparent. For to 
link a ghost to materiality, if it does not discredit 
the materiality, serves to substantialize the ghost. 
Furthermore, it shows that in this case neither the 
one double nor the other can have had its width 
engineered on any preconceived scale, unless the 
twin bays be themselves so accounted for. So that 
it seems useless to seek for cryptic standards in the 
canals or to think to find them a measure of value 
from the fact of their being a medium of exchange. 
A third instance of the same thing in the case of the 
Ganges and the Jamuna was proved at the last oppo- 
sition after having long been suspected without my 

chap, xviii THE DOUBLE CANALS 233 

being able to make sure of it. These instances, taken 
in connection with the wide range of values in the 
widths presented by different canals, serve to show 
that the distance between the twin lines is an individual 
characteristic of the particular canal, and further to 
point to its cause, in some cases certainly and possibly 
in all, as topographical. The duplicate line makes a 
convenience of a neighbor, and suits its distance from 
its fellow to friendly feasibility. To cut a ' canal' to 
conform to the country seems logical if not obliga- 
tory, and quite in keeping with the nomenclature of 
the subject; but here the starting-point appears to be 
the only thing considered the canal once saf el 
launched being left to shift, or rather not shift, for itself 


Topography thus introduced to our notice for its 
effect on the breadth of the doubles proves upon inspec- 
tion to be of extended application to the whole sub- 
ject. Examined for position these canals turn out to 
have something to say for themselves bearing on the 
question of their origin and office. 

With regard to position, probably the first query to 
suggest itself to an investigator to ask is of the direc- 
tion in which they run. /Is there a preponderance mani- 
fest in them for one direction over another ? Do they 
show an inclination to the vertical, to the horizontal, 

234 MARS AND ITS CANALS chap, xvm 

or to some tilt between?) To answer this we may box 
the compass, and taking the four cardinal points with 
the twelve next most important points between for 
sectional division segregate the doubles according to 
their individual trend. As we have no means of deter- 
mining in which sense any direction is to be taken, if 
indeed it is not to be taken alternately in each, we 
get eight compartments into one or the other of which 
all the doubles must fall. This they do in the following 

S. & N., Laestrygon, tFretum Anian, Aethiops, Amenthes, 

Titan, tDis, fls 7 

S. S. E. & X. X. W., fGihon, Ganges, JTithonius, Euphrates, 

Adamas 5 

S. E. & X. W., fEunostos, Triton, Tartarus, Naarmalcha . 4 

E. S. E. k W. X. W., fAstaboras, Typhon, fPierius . . 3 

E. A: \\\, tXar, tProtonilus, *Propontis, J Nectar, fCocytus, 

t Chaos, 6 

E. X. E. A: V* . S. W. tDeuteronilus, tCallirrhoe, tCerberus N., 

Cerberus S., tSitacus, t Erebus . . ... 6 

X. E. & S. W., tDjihoun, *Nilokeras I & II, fAvernus, fNe- 
penthes, Gigas, fAlander, Polyphemus, tGelbes, t Mar- 
gins, tPyramus, fNilokeras I, Asopus . ... 12 

X. X. E. & S. S. W., Jamuna, Phison, fHyblaeus, Cyclops, 

Lethes, tThoth, tVexillum, tHiddekel . _8 


NO conclusively marked preponderance for one direc- 
tion over another manifests itself by this partition- 
nient. Nevertheless, a certain trend to the east of 

* Wide canals. tXorthern hemisphere exclusively. 

t Southern hemisphere exclusively. 

chap, xviii THE DOUBLE CANALS 235 

north, as against the west of north, is discernible. 
More than twice as many doubles run northeast and 
southwest or within forty-five degrees of this as do 
similarly northwest and southeast, there being twelve 
of the latter and twenty-six of the former. That this 
seems to mean something the nearly equal pairing of 
quadrantal points goes to show. Thus : 

N. & S. and E. & W. inclined canals number . . 7 + 6 = 13 

N. N. E. & S. S. W. and E. S. E. & W. N. W. in- 
clined canals number 8+3 = 11 

N. E. & S. W. and S. E. & N. W. inclined canals 

number 12+4 = 16 

E. N. E. & W. S. W. and N. N. W. & S. S. E. in- 
clined canals number 6+ 5 = 11 

33 18 51 

a fairly equable division in direction. A trend to the 
westward would be given a particle descending from 
the north to the equator by the planet's rotation, thus 
turning it southwesterly; and one to the west to a 
particle travelling equatorwards from the south, turn- 
ing it northwesterly. As the doubles lie in the northern 
hemisphere, either in whole or part, to the extent of 
93 %, this might account for the preponderating tilt to 
the east of north and west of south exhibited by them. 
It would correspond with the lines of flow. \ 

To see whether this be so we will take only those 
double canals that lie exclusively in the northern and 
southern hemispheres respectively, and note those in 

236 MARS AND ITS CANALS chap, rna 

the former that trend to the west of south as against 
those that run to the east of it, and vice versa in the 
southern, (in the northern the proportion of the 
westerly to the easterly ones is 17 to 4; in the southern, 
1 to the other way/) 

I M those whose course is common to both hemispheres 
we find for the ratio of the southwesterly to the south- 
easterly 8 to 7. But the proportion of the course of 
these canals in the two hemispheres is on the side of 
this same ratio. 

From their direction we now pass to ^consideration 
of their distribution in longitude. It appears that 
some meridians are more favored than others) The 
hemisphere which has the Syrtis Major for centre is 
more prolific in them than its antipodes, trom longi- 
tude 80 to 200 there are ten doubles, from 200 to 
320 twenty-four, and from 320 to 80 seventeen; or, 
roughly, in the proportion of 2, 5, and 3. That 
this distribution means anything by itself is doubtful) 
it is much more likely to be a general topographical 
consequence of their distribution in another direction, 
which proves to be highly significant and which we 
shall now expose that of latitude. 

I f we separate the surface into zones, each ten degrees 
wide, and count the doubles found traversing in whole 
or pari the several zones, we find the following arrange- 
ment : 




Double Canals of Mars 
arranged according to latitude 

a a 

O P3 

Between 30 S. and 20 S. 

Between 20 S. and 10 S. 

Between 10 S. and 

Between and 10 N. 

Tithonius, Nectar, Laes- 

Jamuna, Ganges, Gigas, 
Laestrygon, Cyclops, 
Titan, Tartarus, Poly- 
phemus, Tithonius 

Jamuna, Ganges, Gigas, 
Laestrygon, Cyclops, 
Cerberus S, Aethiops, 
Lethes, Amenthes, Tri- 
ton, Phison, Euphra- 
tes, Titan, Tartarus, 
Adamas, Typhon, Vex- 
illum, Asopus, Naar- 
malcha, Polyphemus . 

Gihon, Djihoun, Jamuna, 
Ganges, Gigas, Laes- 
trygon, Cerberus N, 
Cyclops, Cerberus S, 
Eunostos, Aethiops, 
Lethes, Amenthes, Tri- 
ton, Nepenthes, Phison, 
Euphrates, Sitacus, 
Hiddekel, Tartarus, 
Adamas, Asopus, Ty- 
phon, Vexillum, Cocy- 
tus, Is, Avernus N, 
Naarmalcha, Polyphe- 








Double Canals of Mars 
arranged according to latitude 

0, < 


l i t 


o i 

Between 10 N. and 20 N. 

Between 20 N. and 30 N. 

Between 30 N. and 40 N. 

Gihon, Djihoun, Jamuna, 
Nilokeras I and II, 1 
Nilokeras I, Ganges, 
Gigas, Eunostos, Aethi- 
ops, Lethes, Amenthes, 
Thoth, Astaboras, Phi- 
son, Sitaeus, Euphrates, 
Hiddekel, Adamas, Aso- 
pus, Gelbes, Avernus 
N, Erebus, Naarmalcha, 
Vexillum, Is, Dis 

Gihon, Djihoun, Jamuna, 
Nilokeras I & II , l Nilo- 
keras I, Alander, Hyb- 
laeus, Lethes, Amen- 
thes, Thoth, Sitaeus, 
Astaboras, Vexillum, 
Phison, Euphrates, 
Hiddekel, Adamas, 
Eunostos, Aethiops, 
Gelbes, Avernus N, 
Naarmalcha, Is . 

Deuteronilus, Alander, 
Nar, Marsias, Fretum 
Anian, Amenthes, 

Thoth, Vexillum, Phi- 
son, Euphrates, Hidde- 
kel, Adamas, Eunostos, 
Djihoun, Gihon, Nilo- 
keras I, Chaos, Gelbes, 
Aethiops, Naarmalcha, 







Very wide and possibly not of the same class. 





S H 

2 > 

H fa 
5 W fe 

Double Canals of Mars 

H fa 

2 < 

O a l 
Ah So 


o o 

ft o 

Ah -4 

H i-i 

ij fa N 
^ O H 
H cc <! 

Between 40 N. and 50 N. Fretum Anian, Pyramus, 

Protonilus, Propontis 1 



Between 50 N. and 60 N. Callirrhoe, Fretum Anian, 




Between 60 N. and 63 N. Pierius, Callirrhoe . 



(From this tabulating of them it is apparent that the 
doubles are practically confined to the zones within 
forty degrees of the equator. Only 7 f> of them straggle 
farther north than this, while above 63 north latitude 
and 35 south latitude there are none!) Such a distri- 
bution is not in proportion to the areas of the zones, 
which though diminishing toward the poles do so 
at no such rate. rThe surface included between the 
equator and 40 of latitude is 65 f> of the hemisphere, 
whereas the fraction of the number of doubles found 
there is 93 % The doubles are, then, an equatorial 
feature of the planet, confined to the tropic and tem- 
perate belts!) 

To perceive the tropical character of the doubles in 
another way we have but to consider the zonal dis- 
tribution of the single canals. Unlike the former the 

1 Very wide and possibly not of the same class. 

240 MARS AND ITS CANALS chap, xv,,, 

latter do not thin out as one advances toward the poles; 
since in the arctic regions single canals bemesh the sur- 
face as meticulously as elsewhere. It is only that they 
there replace the doubles; or, not to put the cart before 
the horse, it is the doubles that in part replace the singles 
in the tropics. And that this arrangement has some- 
thing physical behind it by way of cause is curiously 
shown by two canals, the Arnon and the Kison, which 
are neither of the one kind nor yet the other, but a 
cross between the two. For the Arnon and the Kison 
are convergent doubles; the two lines of the Kison 
leaving a common point at the edge of the polar cap 
and separating as they travel south, while the two 
Anion take up and continue the divergence, connect- 
ing at last with the parallel pair of the Euphrates. 
These canals thus make transition between the true 
doubles and the true singles, and maybe looked upon 
as endowed with the potentialities of both. From 
their association with the double Euphrates, it is clear 
thai the transition between the two forms is not only 
formal bul physical, and that the stopping of the dual 
condition at the fortieth parallel is not the outcome 
of chance. 

It may occur to the thoughtful that the doubles ap- 
pear confined to the more tropical portions of the planet 
because of a better presentation of those zones, the 
reader supposing the planet to be seen axised perpen- 

chap, xviii THE DOUBLE CANALS 241 

dicularly to the plane of sight, as geographies represent 
the earth's globe. The supposition, however, is errone- 
ous. We sometimes see the planet so, but more often 
not. Such is the tilt of the Martian axis to the plane 
of the Martian ecliptic that the different zones are 
rarely seen on an even keel, so to speak, their aspects 
shifting totally from one opposition to another. What 
shows in mid-disk on one occasion may be forty-eight 
degrees removed from it at another, a distance 
amounting to three-quarters of the way from apparent 
equator to apparent pole. 

;Thus the double canals are for some intrinsic reason 
equatorial features of the planet as opposed to polar 
ones. And this not simply because of greater space 
there. Duality is a result of conditions intrinsic to 
the several localities) What the cause may be is re- 
lated to the character of the things themselves, which 
we shall later consider. For the moment we may note 
that the fact disposes quietly of the diplopic theory 
of their manufacture. For, for diplopic doubles to 
show such respect for the equator would betoken a 
courtesy in them to be commended of Sydney Smith. 
But this is not their only geographic bias. (In addi- 
tion to not being partial to the poles, the double canals 
show a certain exclusiveness toward the dark areas 
generally. Not only do they avoid the arctic and ant- 
arctic zones entirely, but they largely shun the blue- 

242 MARS AND ITS CANALS chap, xvm 

green regions In these but two suspicions of doubles 
occur, in the Aonium Sinus, although single canals 
there arc as numerous as anywhere else on the planet. 

Nevertheless, although they avoid running through 
them, they run from them in a manner that is marked. 
Proceeding from the great diaphragm are no less than 
28 out of the 53 doubles. Connecting directly with 
these are 17 more; while the remaining 8 are also asso- 
ciated through the intermediarism of dark areas, the 
Sol is Lacus and the Trivium. 

In like relation to dark regions, they are limited on 
the north by the Mare Acidalium, the Propontis, the 
\Ye< Ige of Casius and their interconnecting bands, the 
Pierius, Callirrhoe, Helicon. In this manner do they 
form a broad girdle round the planet's waist, leaving 
the polar extremities bare. 



/^lEVENTEEN years after the recognition of the 
canals in the light regions occurred another im- 
portant event, the discovery of a similar set in the dark 
ones. ) The detection of these markings in the dark 
areas was a more difficult feat than the perceiving of 
those in the light, and in consequence was later accom- 
plished. Also was it one where recognition came by 

I have previously pointed out what this discovery 
did for the seas nothing less than the taking away 
of their character in a generally convincing manner. 
To one who had carefully considered the matter, 
the seas had indeed already lost it, as was shown in 
Chapter X, but to those who had not these canals 
presented a very instant proof of the fact. 

From such not wholly supererogatory service they 

went on to furnish unlooked-for help in other directions. 

/Their discovery showed in the first place that no part 

of the planet's surface was free from canal triangulatiom) 

But it did more than this. For these canals in the 
dark regions left the edge of the 'continents' at the 


244 MARS AND ITS CANALS chap, xix 

very points where the canals of the light regions entered 
them, which fact proved for them a community .of 
interest with the latter. Such continuation was highly 
significant, since it linked the two together into a single 
system, compassing the whole surface of the planet. 
Starting from the places where the light-region canals 
coi iic out upon the great girdle of seas that stretches all 
round the planet, most of the new canals headed toward 
the passes between the islands south, as nearly pole- 
wards as circumstances of local topography would per- 
mit. In the broader expanses of the Syrtis Major and 
the Mare Erythraeum, besides main arteries others 
went to spots in their midst after the same fashion 
as those of the light regions. These spots differed in 
no way apparently from their fellow oases elsewhere. 
From a spot in the centre of the Syrtis three great lines 
thus traveled south: the Dosaron, heading straight 
up the Syrtis on the meridian till it struck the northern- 
most point of Hellas; the Orosines, inclined more to 
the right, passing through the dark channel to the west 
of that land and so proceeding south; and lastly the 
Erymanthus turning eastward till it brought up finally 
at the Hesperiduin Lucus. Where, on the other hand, 
the long chain of lighter land, called by Schiaparelli 
islands, and stretching from the Solis Lacus region west- 
ward to Hellas, offered only here and there an exit, 
the canals made for these exits. The canals in the Mare 


Sirenum, the MareCimmerium, and the Mare Tyrrhenian 
struck more or less diagonally across those seas from 
their northern termini to the entrances of the straits 
between the islands, thus lacing the seas in the way a 
sail is rolled to its spar. From the exact manner in 
which they connected with the light-region canals they 
proved the two to be part and parcel of one system, 
which in its extension was planet-wide and therefore 
proportionately important. Whatever of strange inter- 
est the curious characteristics of the canals themselves 
suggested was now greatly increased by this addition ; 
for the solidarity of the phenomenon affected the 
cogency of any argument derived from it. 

In 1894 only the dark areas of the southern hemi- 
sphere were found to be thus laced with lines. For then 
so great was the tilt of the planet's south pole toward 
the earth, that while those zones were well displayed 
the dark patches of the northern hemisphere were more 
or less hull-down over the disk's northern horizon. 

Contrast was the open sesame to their detection. 
When the maria show dark, the lines are lost in the 
sombreness of the background. As the maria lighten 
the lines come out. Such was amply witnessed by 
the effect in 1894 and 1896. In 1894 I found it impos- 
sible to perceive them, except where the Padargus 
crossed Atlantis, for the hue of the maria themselves 
was then very dark. In 1896, on the other hand, I saw 

246 MARS AND ITS CANALS ch*p. xix 

them without difficulty. What is also of interest: so 
soon as seen they appeared small, without haziness 
or distention. 

As the oppositions succeeded one another the north- 
ern regions rose into view, and with their appearance 
came the detection in them of the same phenomena. 
No large dark areas like the diaphragm exist there, but 
the smaller patches of blue-green which bestrew them 
proved to be similarly meshed. At first canals were 
evident upon their peripheries, contouring them about; 
then the bodies themselves of the patches showed grid- 
ironed by lines. 

The Mare Acidalium with its adjuncts, the Lucus 
Niliacus on the south and the Lacus Hyperboreus on 
the north, thus stood out in 1901. On a particularly 
good evening of definition at the end of May, the Mare 
suddenly made background for a sunburst of dark rays, 
six of them in all radiating from a point between it and 
the Lacus Hyperboreus. Considering how sombre the 
Mare was at the time, this was as remarkable a vision 
as it was striking to see. Although at the moment 
the sight was of the nature of a revelation, these lines 
have been amply verified since, as the Martian season 
has proved more propitious. 

Similar decipherment has befallen all the other 
patches of blue-green in the northern hemisphere; 
these having shown themselves first circumscribed and 


then travel-see 1 '- - Interesting instances were 

the Wedge of 'a. * wi z Propontis. Tnese mark- 
ings, first perceived years ago as mere patches of shad- 
ing, then partially resolved by Schiaparelli, now stood 
revealed as a perfect network of lines and spots. So 
many of both kinds of their 
detail occupied the ground 
that to identify them all was 
matter of exceeding difficulty. 
The outcome is shown in the 
diagrammatic representations 
opposite and on page 256. The Pr P ntis > 1905 - 

These drawings disclose better than any description 
the mass of detail of which the patches are in reality 
composed, and serve to convey an idea of the com- 
plexity involved. If the general canal system seem 
intricate, here is something which exceeds that as 
much again. 

The extension in this manner of the curious trian- 
gulation of the light areas into and through all the 
dark areas as well, by thus spreading the field of its 
operations over both terranes complexioned so unlike, 
greatly increases the cogency of the deduction that this 
detail is of later origin than the background upon which 
it rests. That the mesh of lines covers not only the 
ochre stretches of the disk, but the blue-green parts as 
well, makes it still more certain that it is not a sim- 

248 MARS AND ITS CANALS chap, xix 

pie physical outcome of the fundamental forces that 
featured the planet's face. For in that case it could 
not with such absolute impartiality involve both alike. 
Thus here, again, we find corroboration by later ob- 
servations of what earlier ones established. 

A last link in the chain of canal sequences remains 
to be recorded. [Just as the lines in the dark regions 
continued those in the light, so they themselves turned 
out to be similarly prolonged and in no less suggestive 
a manner. For when the north polar zone came to be 
displayed, canals were evident there, continuing those 
in the other zones and running at their northern ends 
into dark spots at the edge of the polar cap. Here, 
then, we have the end of the whole system, or more 
properly its origin, in the polar snowso The signifi- 
cance of this will be seen from other phenomena, to a 
consideration of which we now proceed. 



"VTEXT to be caught of the details of this most curi- 
ous network that meshes the surface of Mars was 
a set of phenomena stranger even than the lines ; to wit, 
dark round dots standing at their intersections^ More 
difficult to make out than the lines, they were in conse- 
quence detected thus later by fifteen years. Once 
discovered, however, it became possible to trace their 
unconscious recognition back in time. Thus Schiapa- 
relli told the writer in 1895, apropos of those found at 
Flagstaff, that he had himself suspected them but could 
not make sure. Some of them stand figured in his 
Memoria Sesta dealing with the opposition of 1888, but 
not published till 1899. In such posthumous recogni- 
tion, as one may call it, the spots repeated the history 
of the canals. For Schiaparelli had himself pointed 
out a similar preconscious visioning of the canals in 
the delicate pencilings of Dawes and the streaks of 
Lockyer, Kaiser, and Secchi, now translatable as rep- 
resenting the Phison, the Euphrates, and half a dozen 
other canals imperfectly seen. That both the canals 
and the oases were thus sketched before they were seen 


250 MARS AND ITS CANALS chap, xx 

well enough to be definitely discovered is to an un- 
prejudiced mind among their strongest credentials to 

Nor was Schiaparelli the sole person thus to get proof 
before letter. One of their very earliest portrayals 
appears in a drawing by Otto Boeddicker, made on 
December 26, 1881, where the Pseboas Lucus is clearly 
represented. In a still more imperfect manner some 
of the spots had been adumbrated and their shadows 
drawn long before that. Thus they may be deciphered 
as the cause of patches drawn by Dawes in 1864, 
though none of them were in any definite sense de- 
tected till 1879, and only then so ill defined that their 
true character was not apparent. As patches they are 
still commonly seen at observatories where the obser- 
vational conditions are not of the best and the study 
of the planet not systematically enough pursued to have 
them disclose their true shape and size. 

The history of their detection is resumed in the 
experience of the individual observer. During the 
course of my own observations I have had occasion to 
notice the several stages in recognition of the spots 
which have marked their chronologic career. /As with 
the lines, three stages in the appearance of the spots 
may be remarked: first, where the scattering of the 
rays is so wide that dilution prevents anything from 
being seen; second, where the commotion being less 

chap, xx OASES 251 

the object appears as a gray patch; and third, where 
in comparative quiet it condenses into a black dot. 
For the two former our own air waves are to blamed) 
In coursing waves of condensation and rarefaction they 
spread the image of the spot as they do that of the 
canal. Then as the currents calm the spot shrinks 
to its normal proportions, and in so doing darkens in 
consequence of being less widely diffused. Thus the 
evolution in perception which may take place in the 
course of an hour for a particular observer represents 
exactly what has occurred in the person of the race by 
the improvement in observational methods and sites. 
(That the spots, although wider than the canals, re- 
mained longer hidden from human sight, is due to the 
optico-physic fact that a tenuous line may be perceived 
owing to its length when a dot of the same diameter 
would be invisible) Summation of impressions is un- 
doubtedly the cause of this. The mere fact that a row 
of retinal cones is struck, although each be but feebly 
affected, is sufficient to raise the sum total into the 
sphere of consciousness. 

In the second stage of their visibility, the spots are in 
danger of mistake with the smaller true patches of som- 
bre hue which fleck the northern hemisphere of the 
planet and from which they differ totally in kind, totally 
so far as our present perception goes. Such true 
patches consist of a groundwork of shading, upon which, 

252 MARS AND ITS CANALS chap, xx 

indeed, are superposed the usual network of lines and 
spots. Prominent as instances of them are the Trivium 
Charontis, the Wedge of Casius, and the Mare Acidalium. 
With patches of the sort the spots proper must not be 

Close treading on the heels of the detection of lines 
athwart the seas came the recognition of spots there 
likewise. At the opposition of 1896-1897 the num- 
ber was added to; and so the tale has been steadily 
increased. ^Their number as found at Flagstaff up to 
the present time, that is, to the close of the opposition 
of 1905, is 186; of which 121 lie in the light regions, 
42 in the dark areas of the southern hemisphere, and 
23 in the smaller sombre patches of the northern zones} 

From their relationships and behavior it became 
apparent that the spots were not lakes but something 
which answered much more nearly to oases. 

Of the spots three kinds may be distinguished: the 
large, the little and the less, if by the latter term it may 
be permitted to denote what has but collateral claim 
to be included and yet demands a certain recognition. 
For though not spots like the others, the members of 
the third class have certain traits in common with them 
while differing radically in others^ 

To the kind called large belong the greater number 
of spots so far found upon the disk. They are large 
only by comparison with the little. For they measure 

chap, xx OASES 253 

according to my latest determinations but seventy- 
five or one hundred miles in diameter ; on the planet 
some two degrees across. Sizable black pin-heads, 
it is their tone that chiefly catches the eye, for they 
are commonly the darkest markings on the disk. 
Against the ochre stretches they appear black, and 
even in the midst of the dark areas they stand out 
almost as much contrasted with their surroundings 
as these do with the light regions themselves. About 
a hundred and forty are now known) Those in the 
light areas were discovered first; those in the dark 
regions being harder to see. 

Of this first kind are such spots as the Pseboas Lucus, 
the Aquae Calidae,the Lacus Phoenicis, and the Novem 
Viae; or, in English, the Grove of Pseboas, the Hot 
Springs, the Phoenix Lake, and the Nine Ways, to men- 
tion no more. That they bear dissimilar names implies 
no dissimilarity in structure. ('The phenomena are all 
remarkably alike, and clearly betoken one and the 
same class of objects; differing between themselves 
at most in size and importance. 

In form they all seem to be rounds ( They certainly 
appear so, and were it not that retinal images of small 
areas tend to assume this shape might implicitly be 
credited with being what they seem. The reason for 
optical circularity probably resides in the shape of the 
retinal cones and in their patterning into a mosaic 

254 MARS AND ITS CANALS chap, xx 

floor. So that unless a sufficient number of cones be 
struck the image takes on to consciousness a roughly 
circular figure whether it be so in fact or not. In 
the present case, however, they seem to be too well 
seen for self-deception of the sort. 

The little are distinguished from the large by being 
pin-points instead of pin-heads. They are most mi- 
nute; from fifteen to twenty-five miles in diameter 
only. That anything except size distinguishes the 
two apart is from their look improbable. In color or 
rather tone, for distinctive color is of such minute 

objects unpredicable, they 
would seem to be alike. 
Such is also the case with 
their distribution and detail 

To the second class be- 
long the Fons Juventae, 
Schiaparelli's Fountain of 
Youth, the Fons Immor- 
talis in Elysium in 1905, and the Gygaea Palus, besides 
many more. These are all pin-points, just upon the 
limit of vision, and noteworthy chiefly for being visible 
at all. All those detected so far lie not very distant 
from the equator, which may or may not be a matter of 
accident. It is not one of perception, since this part 
of the planet was not the best place for observation at 

' chap, xx OASES 255 

the time they were discovered. To make out one of 
these little dots is a peculiarly pleasing bit of observa- 
tion, as it requires particularly good definition. One 
might almost take them for fly-specks upon the image 
did they not move with the disk. (They have no per- 
ceptible size and yet are clearly larger in diameter than 
the canals which run into them; which proves how 
very slender the latter must be. 3 

Very early in the detection of the spots it became 
evident that they were not scattered haphazard over 
the surface, but that on the contrary (they were never 
found except at the meeting-points of the lines) From 
this it must not be supposed, as has been done, that the 
spots are merely optical reinforcements of the lines at 
their crossings due to the more crowded character 
there of the lines themselves. That they are not such 
is demonstrated by the existence of crossings where, 
either temporarily or permanently, none appear; 
which shows that they are far too well seen for any 
such illusion about them to be possible. At these cross- 
ings the lines traverse one another without thickening, 
whether they be single or double lines. The spots, 
on the other hand, are much wider than the lines, 
giving a beaded look to the threads. In short, they 
are the knots to the canal network. All the more im- 
portant junctions are characterized by their presence. 
Such starred junctions are not confined to the ochre 



regions; they dot the light and the dark areas with 
equal impartiality, thus showing themselves to be in- 
dependent of the nature of the ground where large 
st retches of country are concerned. On the other hand, 
they appear to be unusually numerous in the smaller, 
isolated, dark areas of the northern hemisphere^ such 

as the Trivium, the Mare Acidalium, the Propontis, 
and the Wedge of Casius. (Here they crowd; and one 
cannot avoid the inference that their plentifulness in 
these regions is not due to chance^ 

/To the large spots, those of the first class, fall the 
places of intersection of the largest and most numer- 
ous canals, while the little spots make termini to 
fainter lines, ones that bear to them a like ratio of un- 
importance. Spots and lines are thus connected not 
simply in position but in size> The one is clearly 
dependent on the other, the importance of the centre 
being gauged by the magnitude of its communications. 

chap, xx OASES 257 

From the fact of association we now pass to the man- 
ner of it, which is quite as remarkable. (The position 
of the spot relative to its tributary canals depends upon 
the character of the connecting lines. If the canal be 
single it runs, so far as may be judged, straight into 
the middle of the oasis, or, in other words, the oasis 
is symmetrically disposed about its end. This is true 
of the greater number of the large spots and of all the 
little ones, since the latter have as connections only 
single canalso 

(In the case of a double canal arriving at a spot, a differ- 
ent and most curious dependence is observable) This 
fact I first noticed in a general way at the opposition of 
1896-1897, the initial appearance of it being presented 
on September 30, 1896, by the Coloe Palus and the 
Phison. It was again visible in the case of the spots 
in the Trivium at the time the canals leading to that 
place doubled in March, 1897. But the exact nature 
of the phenomenon was not fully appreciated till 
1903, when the thing was seen so well as to appear 
cut on copper plate. It was this : the spot is exactly 
embraced between the two arms of the double canal. 
It is, moreover, seemingly perfectly round and just 
fits in between the parallel finest The Ascraeus Lucus 
was the first spot that showed thus in association with 
the double Gigas. Others followed suit in so showing, 
several specimens presenting themselves so well as to 


Leave no doubt of the precise connection. The_sight 
presented by such a spol and its incasing double is a 
beautiful bit of detail, perhaps the most beautiful so 
far to be seen upon the Martian disk. The distinct- 
ness with which it stands out on occasion suggests 

a steel engraving, 
and shows how 
clear-cut the Mar- 
tian features really 
are when our own 
air ceases from 
/***. troubling and al- 

lows them to be 
at rest. Incidentally, we may note that this phe- 
nomenon alone serves to disprove the diplopic theory 
of the production of the double canals. For if a double 
were a single line seen out of focus, any spot upon it 
should be doubled too. 

It may seem to the reader as if what was seen 
in 1903 was but an unimportant advance over the 
ol >served phenomena of 1896-1897. Not so, however. 
For with the earlier instances it was not possible 
to be sure of the precise limits of the spot with regard 
to the double. The Coloe Palus, on the one hand, did 
not fill all the space apparently between the double 
Phison; while the Lucus Ismenius more than did so 
with the double Euphrates. To have set down the 

chap, xx OASES 259 

different appearances to insufficient definition would 
have been a great mistake, as subsequent observation 
has served to show. The Lucus Ismenius instances 
this. In 1896-1897 it was seen terminating the Eu- 
phrates, blocking all the space between the two lines 
and extending a little upon either side of them. Now, 
from its appearance in 1901 it was evident that the 
effect had been produced by twin spots lying along 
the Deuteronilus, the axis joining them being perpen- 
dicular to the Euphrates. In 1903 the relation was 
still better explained by what appeared then, when not 
only did the two spots stand out, but the Euphrates 
showed with a line running centrally into each. 

Although originally seen by Schiaparelli as a single 
spot and so at first seen by me, better acquaintance 
with the disk disclosed to both observers its really dual 
character. As this pair has persisted through all three 
of the most recent oppositions, it seems fairly certain 
that it is always of this character, and more fitting, 
therefore, to give it the plural appellative. ( This 
is the single instance of a double oasis/) There are 
many that lie close together and might be taken as 
such; but this is the only one where the connection is 
intrinsic. According to measures of the drawings of 
1905 extending through six presentations, the distance 
between the twin oases is 4. 2. 

Their relation to the canals which run into them is of 



the most complicated description and of the most sug- 
gestive character. For to the twin spots converge 
no less than seven double canals, one wedge-shaped 
pair and three single canals, a most goodly number of 
communication lines. Four of the double canals run 
into the oases with one line to each ; these canals are 
the Astaboras, the Naarmalcha, the Euphrates, and the 
Hiddekel. Three doubles, the Protonilus, the Djihoun, 
and the Deuteronilus, embrace the oases between their 
two lines, while, in the singles, the canal connects with 
one or other of the twins, as the case may be] 

Now, there is method as to which of the doubles 
shall straddle, which embrace, the two Ismenii. CThose 

which leave the place parallel 
or nearly so to the direction 
joining the Luci, inclose 
them both; those of which 
the. setting forth is at an 
angle to this direction depart, 
each line of the pair, from 
the eastern and the western 
spot respectively} 
Consider, now, the dispo- 
sition of these seven pairs of lines. All of them lie in 
one semicircle about the Luci, beginning with the 
Protonilus on the east and ending with the Deuter- 
onilus on the west. Furthermore, all follow approxi- 

Peculiar association of the Luci 
Ismenii with double canals. 




mately arcs of great circles, except the Djihoun, and 
all send one of their twin lines to one Lucus, one to 
the other. The data are enough to make this state- 
ment possible. Although the west line of the Naar- 
malcha has not been caught entering its oasis, the east 
one has been seen to enter the other, and the width of 
the double shows that the west one must enter the 
corresponding spot. In the case of the Astaboras the 
double has only been observed as far as the Vexil- 
lum, but the south line has continued on to the west 
Ismenius, and here again the width makes it certain 
that were the canal double throughout, the other line 
must enter the east Ismenius. From the base line of 
the Proto-Deuteronilus the inclinations of the seven 
pairs are as follows : 





Hiddekel . 

Djihoun . 


Due East 
40 North of East 
70 North of East 
80 North of West 
55 North of West 

North of West 

Due West 

Now, the width between the two lines of the four canals 
to the east increases regularly from the Protonilus 
round ; the Protonilus being the narrowest double, the 
Astaboras the next, the Naarmalcha the next, and the 
Euphrates the widest. And from the width between 
the twin oases, it would seem that they severally enter 

262 MARS AND ITS CANALS chap, xx 

the centres of them. What takes place in the case of 
the Hiddekel, which is wider than its tilt would imply, 

and in the Dji- 

houn, which is 

\ V/ / narrower, is not 

^Wt^ so clear. But 

that they enter 
L** l/*tL. ^M^.tf**: the oases in some 

place is certain. 
The spots make 
common termini for all the canals of a given neigh- 
borhood. In other words, canals converge to the 
places occupied by the spots and do not cross hap- 
hazard according to the laws of chance. Only one 
instance exists where a spot fails to gather to itself 
the whole sheaf of canals and even there it collects 
all but two. This anomaly is the Pseboas Lucus. 
The peculiarity of this oasis is that it lies not on, 
but just off, the Protonilus. That it does so is ex- 
ceeding curious, considering that it is the sole example 
of such extra-canaline position. Strictly speaking, it is 
not the Protonilus but the point where the Protonilus 
turns into the Xilosyrtis to which it stands thus neigh- 
boring! v aloof. And this may explain the anomaly. 
For the Xilosyrtis has not the full geometric regu- 
larity of the normal canal, and seems to have been 
a more or less fundamental feature of the region. 

chap, xx OASES 263 

For the rest, the Lucus has the form and possesses 
the canal connections appropriate to its state. It is 
apparently round, and lies between the twin lines of the 
Phison and also between those of the Vexillum. 

Not far from the Pseboas Lucus are to be found all 
the examples of the third class of spots ; for so far they 
have not been observed outside of Aeria, a region pe- 
culiarly peopled by double canals. With double canals 
they are necessarily associated, inasmuch as they con- 
sist of shading in the form of a square or parallelogram, 
filling the deltas between two pairs that cross. Thus 
have shown the Coloe Palus at the crossing of the double 
Phison with the double Astaboras, and the Juturna 
Fons where the double Sitacus traverses the double 

At these same places a fourth kind is sometimes no- 
ticeable : a four-square set of pin-points or a two-square 
set of the same at the corners of the line -made parallelo- 
gram. This kind may well be synchronous with the 
third, though it has only been noticed at consecutive 
presentations. The third, however, has no observed 
dependence upon the first or second classes. And this 
serves to make more probable the true objectivity 
of the circular and the square figures respectively 
shown by each. 

(The spots apparent in the dark regions do not appre- 
ciably differ in either size or shape from the bulk of 

204 MARS AND ITS CANALS chap, u 

those visible in the light. Equally with them they 
seem to be round, small, and nearly black. They 
would seem, too, in the great diaphragm or larger 
contiguous sombre region to be equally plentifully 
distributed .\ 



T^UNCTIONALLY related to the canal system, 
-*- and yet in look and location contrasted with its 
other details, is a further set of markings, detected by 
me in 1894, and reseen at subsequent oppositions 
since, along the north border of the southern seas. 
They lie upon what used to be thought the con- 
tinental coastline, the fringing edge of that almost 
continuous band of shading that belts the Martian 
globe throughout the southern subtropic zone and 
called by Schiaparelli the great diaphragm. The ter- 
rane lends itself to the appellative, forming, as it does, 
a dark dividing strip of country between the brilliant 
reddish-ochre hemisphere on the north and the half- 
toned islands to the south of it. By Schiaparelli it 
was thought to be one long Mediterranean, and though 
its marine character is now disproved, that it lies 
lower than the bright ochre regions is likely. To this 
difference of level is probably due the peculiar phe- 
nomenon which there manifested itself to careful scru- 
tiny in 1894. For it was there only that it occurred. 
The phenomenon in question consisted of nicks in 


266 MARS AND ITS CANALS chap, xxi 

the coastline, of triangular shape and filled with shad- 
ing. They occurred at intervals along it and were of 
the general form of carets, such marks as one makes 
in checking items down a list. Their position was al- 
ways where a canal debouched from the diaphragm 
upon its career across the open continent. The canal 
itself was by no means necessarily visible. On the 
contrary, at first it was usually absent. Such was the 
case with those marking the departure-points of the 
Phison and Euphrates and of the Amenthes and 
Let lies, which appeared, without being well defined, 
from the moment the planet came to be scanned. 

One by one these carets stood out to view, punctuating 
the points where canals later were to show or termi- 
nating those that already existed. Strung thus with 
them at intervals was the whole coastline of the dia- 
phragm, beginning with the Mare Icarium and stretch- 
ing round through the Mare Tyrrhenum, Mare Cim- 
merium, Mare Sirenum, and Mare Erythraeum to the 
Marc Icarium again. As the planet got nearer to the 
earth their peculiar shape began to define itself, and it 
was again in the case of those giving origin to the Phison 
and Euphrates that the recognition came first. What 
had appeared earlier simply as a spot now stood out 
;>s two triangular notches, indenting the coast and giving 
exit at their apices, the eastern one to the Phison, the 
western to the Euphrates. These were the things, 


then, that had constituted the Portus Sigaeus of Schia- 

Commonly the carets lie at the bottom of well-marked 
bays, as, for example, those terminating the Syrtis 
Minor and the Sinus Titanum. But frequently they 
are placed in the very midst of a long and otherwise 
unaccented coast, as is the case in mid-course of the 
Mare Cimmerium and the Mare Sirenum. Yet in no 
instance is the thing unassociated with a canal. In 
every case one or more canals leave the caret for their 
long traverse down the disk. 

This is not their only canal connection. When the 
canals in the dark regions came to be discovered, each 
of them was found by me, as nearly as difficult obser- 
vations would permit, to be associated with the caret 
upon its other side. Thus the lacing of the Mare Cim- 
merium and Sirenum used them as its reeving-points. 
Similarly those at the mouths of the Phison and Eu- 
phrates did duty likewise to the Maesolus and the Ion. 
In such manner the carets stood in dual relation to 
canals ; subserving a purpose to the light-region canals 
on the one hand and to the dark-region ones on the 
other. In a way the caret, then, holds the same position 
toward the canals that do the spots in the light or dark 
regions. Like them it is a canal-distribution point. 
Unlike them, however, in shape it is triangular instead 
of round, and we are piqued to inquire to what cause 


it can owe its different contour. The answer seems to 
lie in the character of the locality, not simply in its 
complexion. For the spots in both the northern and 
the southern dark patches are as circular as those stand- 
ing in the light, whether they lie in the centre or upon 
the edges of them. The edges of the northern patches, 
however, and the other sides of the southern ones do 
not present the clear-cut character of the northern coast 
of the diaphragm. Where they seem to be definitely 
bounded they are so by darker canals. This hints 
that their contours are not defined by antithesis of 
level, while that of the northern coast of the great dia- 
phragm is. Difference of altitude is then concerned in 
their constitution; the canal system here falls to 'a 
lower level, and these triangular spots instead of round 
ones are the result. Topographic only, such explana- 
tion leads the way to a more teleologic one, and serves 
even on first acquaintance to stir curiosity to some 
satisfying cause. 

Suggestive in several ways for its resemblance to the 
carets is another detail not far distant from the Portus 
Sigaei, the twin-forked Sabaeus Sinus. Curiously 
enough, this feature of Mars, which has been well 
known and recognized ever since the eagle-eyed Dawes 
detected it more than forty years ago, proves to be a 
sort of connecting link between the main markings and 
the details of more modern detection. The twin- 


forked Sabaeus Sinus, as its name implies, is of the 
form of a double bay ; was considered to be one in fact 
so long as the maria were held to be seas. It straddles 
the point of land which, called the Fastigium Aryn, 
has been taken for the Greenwich of Martian longitudes. 
Each ' bay ' not in truth a bay at all indents 
the ochre in an acute triangle, from the tip of which 
many canals proceed like the rays of a fan from a hold- 
ing hand. Both tips are darker than the main body 
of the dark mare from which they proceed. They thus 
recall in general character the carets. They further 
reproduce specifically the Portus Sigaei, for they give 
origin to two doubles, the Gihon and the Hiddekel, 
in exactly the same manner that the two nicks of the 
Portus Sigaei do to the Phison and Euphrates. Nor 
are their tips much farther apart than those of the 
Portus, five degrees measuring the spread of the one 
and four degrees that of the other respectively; the 
reason for their earlier discovery lying in their greater 
size. They thus perform the same office as the Portus 
Sigaeus, are quite comparable to it in width, and differ 
in shape only as a larger and more acute triangle differs 
from a smaller and blunter one. Undreamt of by 
Dawes and unheeded since, they were the first hint to 
the world of the duality which forms so strangely per- 
vasive a feature of the canal system of the planet. 
Thus the carets stand connected with the canals 

270 MARS AND ITS CANALS chap, xxi 

quite as intimately as the oases but in a significantly 
different manner. For, in addition to their intermedi- 
ary standing between the light regions and the dark, 
their relation to the doubles is peculiar. An instance is 
offered by the double Euphrates and another by the 
Ganges. The Euphrates, as we saw in Chapter XVIII, 
leaves the Portus Sigaei at the south, one line leaving 
each caret centrally, so that each caret is concerned only 
with its own line and has no connection with its fellow. 
At their northern ends both lines have similarly each 
its own Lucus Ismenius. The like seems to be true of 
the Ganges. Similarly the twin Titan, have each its 
own. Such twin duty in the matter of doubles seems 
to be the rule with the carets, even more so than with 
the oases; and this is probably from the fact that the 
coastline is of more limited extent than the interior. 

Altogether the carets offer to our inspection glosses 
in finer print upon the general text of the canals. 
Thought upon what they show takes us a step farther 
toward the solution of the strange riddle of this other 
world, a riddle which he who runs may not read, still 
less scout, and which only reasoning, without prejudice 
or partiality, can unravel. 



"OHOTOGRAPHY holds to-day a place of publicity 
in the exposition of the stars. Directed by Draper 
to the heavens thirty-four years ago, the camera re- 
corded then the first picture ever taken of the moon. 
From this initial peering into celestial matters, practice 
has progressed until now the dry plate constitutes one 
of the most formidable engines in astronomic research. 
Not most effectively, however, in the field which might 
have been predicted. Beautiful as the lunar present- 
ment was, as a presentiment of what was coming, it 
pointed astray. For it is not in lunar portrayal, su- 
perbly as its crater walls in crescent chiaroscuro or its 
crags that cast their tapering shadows athwart the dial 
of its plains stand out in the latest photographs of our 
satellite, that the camera's greatest service has since 
been done. Impressive as they are, these pictorial 
triumphs are chiefly popular, and appeal on their face 
to layman and scientist alike. Not in the nearest to 
us of the orbs of heaven, but in the most remote has 
celestial photography's most prolific field been found 
to lie. Its province has proved preeminently the stars, 


272 MAKS AND ITS CANALS chap, xzn 

especially the farthest off, and that star-dust, the 
nebulae, from out of which the stars are made. Reason 
for this explains at once its efficiency and its limitations. 

Its rival, of course, is the eye. It is as regards the 
eye that its comparative . merits or demerits stand to 
be judged. Now, thus viewed, its superiority in one 
respect is unquestionable; it simply states facts. 
Hut though it cannot misinform, it can color its facts 
by giving undue prominence to the effect of some rays 
and suppressing the evidence of others, so that its 
testimony is not, it must be remembered, always in 
accord with that of human vision. Speaking broadly, 
however, it is so little complicated a machine as to 
register its results with more precision than the retina. 
The evidence of the camera has thus one important 
advantage over other astronomic documents: it is im- 
personally trustworthy in what it states. Bias it has 
none, and its mistakes are few. Imperfections, indeed, 
affect it, but they are of purely physical occasion and 
may be eliminated or accounted for as well by another 
as by the photographer himself. 

In trustworthiness, then, so far as it goes, it stands 
commended; not so much may be said of its ability. 
This depends upon the work to which it is put. In cer- 
tain lines it asserts preeminence; in certain others it is 
so far behind as to be out of the race. The reason for 
both is one and the same, for, as the French would 


say : It has the faults of its quality. The very trait 
that fits it for one function, bars it from the other. 
This excellence is that by which the tortoise outstripped 
the hare, a plodding perseverance. Far less sensitive 
than the retina the dry plate has one advantage over its 
rival, its action is cumulative. The eye sees all it can 
in the twentieth of a second ; after that its perception, 
instead of increasing, is dulled, and no amount of 
application will result in adding more. With the dry 
plate it is the reverse. Time works for, not against it. 
Within limits, themselves long, light affects it through- 
out the period it stands exposed and, roughly speaking, 
in direct ratio to the time elapsed. Thus the camera 
is able to record stars no human eye has ever caught 
and to register the structure of nebulae the eye tries to 
resolve in vain. 

Where illumination alone is concerned the camera 
reigns supreme; not so when it comes to a question 
of definition. Then by its speed and agility the eye 
steps into its place, for the atmosphere is not the 
void it could be wished, through which the light-waves 
shoot at will. Pulsing athwart it are air- waves of 
condensation and rarefaction that now obstruct, now 
further, the passage of the ray. By the nimbleness of its 
action the eye cunningly contrives to catch the good 
moments among the poor and carry their message to the 
brain. The dry plate by its slowness is impotent to 

274 MARS AND ITS CANALS . chap, xxh 

follow. To register anything, it must take the bad with 
the better to a complete confusion of detail. For the 
air-waves throw the image first to one place and then 
to another, to a blotting of both. 

All of which renders the stars, where lighting counts 
for so much and form for so little, the peculiar province 
of celestial photography. With the study of the sur- 
faces of the planets the exact contrary is the case. With 
most of them illumination is already to be had in 
abundance; definition it is that is desired. What suc- 
ceeds so excellently with the stars is here put to it to 
d( > anything at all. At its best, the camera is hopelessly 
behind the eye when it comes to the decipherment of 
planetary detail. To say that the eye is ten times the 
more perceptive is not to overstep the mark. To try, 
therefore, here to supplant the eye by the camera 
is time thrown away. 

Of scant importance to the expert in such matters as 
Mars, there is a side of the subject in which service 
might be hoped of it: that of elementary exposition. 
Congenitally incapable of competing with the eye in 
discovery, the most that, by any possibility, could be 
looked for would be a recording of the coarser details 
after the fact. For this reason it had long been a 
purpose at Flagstaff to photograph some at least of 
the canals. Hut the project seemed chimerical. To 
got an image suitable at all some seconds of exposure 


would be required, and during such time the shifting 
air-waves would blur the very detail desired to be got. 
It was a problem of essential premises mutually anni- 
hilative. The more the would-be photographer should 
avoid the one, the more he would fall into the other. 
Nevertheless the thing was tried in 1901. In 1903 
the subject was taken up by Mr. Lampland, then new 
at the observatory. The results were better than 
those of two years before, the images more clear-cut 
but still incommunicable of canals. Still they were 
satisfactory enough to spur to increased endeavor, and 
during the following interopposition preparations were 
made to grapple with the planet as successfully as could 
be devised at its next return. This happened in 
May, 1905. It then showed a disk only 17" in diam- 
eter, or y^q of that of the moon, and this disk Mr. 
Lampland attacked with the 24-inch and a nega- 
tive amplificator that increased the focal length of the 
former to 143 feet. At such focus the planet's image 
was received upon the plate. Everything that could 
conduce to success had been put in requisition. To 
this end of better definition the color curve of the ob- 
jective was first got, and for it a special color screen 
constructed by Wallace. In spite of its name no achro- 
matic is so in fact, but brings rays of different tint to 
different focus. The color curve shows where these 
severally lie, and the color screen, a chemically tinted 

276 MARS AND ITS CANALS chap, xxn 

piece of glass, is to absorb all those which would blur 
the image by having a different focus from the ones re- 
tained. Next, all manner of plates were tried. For 
in these again it was necessary to reconcile two con- 
tradictory characters, a rapid plate and a well- 
defining one. For the coarser the grain the speedier 
the plate; and coarse grain disfigures the detail. 
Both qualities on so small an image were obligatory 
and yet both could not be got. Then the clock 
had to be as smooth-running as possible. So by a sug- 
gestion of Mr. CogshalFs one was obtained that filled 
this requisite, a new form of conical pendulum. Upon 
this a further refinement was practiced. Ordinarily 
clockwork is timed to follow the stars ; this was altered 
to follow the planet, and so keep it more nearly mo- 
tionless while its picture was being taken. Then the 
device of capping down the telescope to suit the air- 
waves, which had been found so effective to the bringing 
out of fine detail, was put in practice. Lastly, all de- 
velopers were tried, and those found suited to the 
finest work were used. 

Many pictures were taken on each plate one after 
the other, both to vary the exposure and to catch such 
good moments as might chance. Seven hundred images 
were thus got in all; the days of best definition alone 
being utilized. The eagerness with which the first 
plate was scanned as it emerged from its last bath may 


be imagined, and the joy when on it some of the canals 
could certainly be seen. There were the old configura- 
tions of patches, the light areas and the dark, just 
as they looked through the telescope, and never till 
then otherwise seen of human eye, and there more mar- 
velous yet were the grosser of those lines that had so 
piqued human curiosity, the canals of Mars. He who 
ran might now read, so that he had some acquaintance 
with photography. By Mr. Lampland's thought, as- 
siduity, and skill, the seemingly impossible had been 

After the initial success was thus assured, plates were 
taken at other points around the planet and other well- 
known features came out; "continents" and "seas," 
"canals" and "oases," the curious geography of the 
planet printed for the first time by itself in black and 
white. By chance on one of the plates a temporal 
event was found registered too, the first snowfall of the 
season, the beginning of the new polar cap, seen visually 
just before the plate happened to be put in and repro- 
duced by it unmistakably. Upon the many images 
thirty-eight canals were counted in all, and one of them, 
the Nilokeras, double. Thus did the 'canals at last 
speak for their own reality themselves. 




canals: kinematic 

QO far in our account of the phenomena we have 
regarded the lines, the spots, and everything that 
is theirs solely from the point of view of their appearance 
at any one time. In other words, we have viewed 
them only from a static standpoint. In this we have 
followed the course of the facts, since in this way were 
the canals first observed. /We now come to a different 
phase of the matter, the important disclosure, with 
continued looking, that these strange things show them- 
selves to be subject to change. That is, they take 
on a kinematic character. This at once opens a fresh 
field of inquiry concerning them and widens the horizon 
of research. It increases the complexity of the prob- 
lem, but at the same time makes it more determinate. 
For while it greatly augments the number of facts 
which must be collected toward an explanation of 
what the things are, these once acquired, it narrows 
the solution which can apply to them. 

The fact of change in the Martian markings forces 
itself upon any one who will diligently study the planet. 
He will be inclined at first to attribute it to observa- 


282 MARS AND ITS CANALS chap, xxm 

tional mistakes of his own or his predecessor's making, 
preferably the latter. But eventually his own delinea- 
tions will prove irreconcilable with one another, and 
he will then realize the injustice of his inference and 
will put the cause, where indeed it rightly belongs, on 
the things themselves. Confronted by this fact he will 
the more fully appreciate how long and systematic 
must be the study of him who would penetrate the 
planet's peculiarity. Just as the recognition of some- 
thing akin to seasonal change came to Schiaparelli, be- 
cause of his attending to the planet with an assiduity 
unknown to his predecessors; so it became evident 
thai to learn the laws of these changes and from 
them the meaning of the markings, there was necessary 
as full and as continuous a record of them as it was pos- 
sible to obtain. For this end it was not enough to get 
observations from time to time, however good these 
might be, but to secure as nearly as might be a complete 
succession of such, day after day, month after month, 
and opposition after opposition. The outcome justified 
the deduction. And it is specially gratifying to realize 
that to no one have the method and the results thus 
obtained appealed with more force than to Schiaparelli 

Perseverance in scanning the disk long after the 
casual observer had considered it too far away for 
observational purposes, resulted in Schiaparelli's detec- 

chap, xxm CANALS: KINEMATIC 283 

tion of the canals, and this through a characteristic 
of theirs destined to play a great part in their history, 
their susceptibility to change. He tells us in his Me- 
moria I how Aeria and the adjoining regions showed 
blank of any markings while the planet was near in 1877 
and the disk large and well shown, and then how, to his 
surprise, as the planet got farther away and the disk 
shrank, lines began to come out in the region with un- 
mistakable certainty. Thus to the very variability 
which had hidden them to others was due in Schia- 
parelli's hands their initial recognition. 

Flux affecting the canals was apparent from the 
outset of my own observations. No. less the subject 
of transformation than the large dark regions was the 
network of tenuous lines that overspread them. At 
times they were very hard to make out, and then again 
they were comparatively easy. Distance, instead 
of rendering them more difficult, frequently did the 
reverse. Nor was the matter one of veiling. Neither 
our own atmosphere nor that of Mars showed itself 
in any way responsible for their temporary disappear- 
ance. It was not always when our atmospheric con- 
ditions were best that the lines stood out most clearly, 
and as to Martian meteorology there was no sign that 
it had anything whatever to do with the obliteration. 
Long before the canals were dreamt of, veiling by 
Martian clouds or mist had been considered the cause 

284 MARS AND ITS CANALS chap, xxm 

of those changes in the planet's general features, which 
are too extensive and deep-toned wholly to escape ob- 
servation even though none too clearly seen. It was 
<arlv evident to me that they were not the cause of 
general topographic change, and equally clearly as 
inoperative in those that affected the canals. In short, 
nothing extrinsic to the canal caused its disappearance; 
whatever the change was, its action lay intrinsic to the 
canal itself. 

On occasion canals in whole regions appeared to be 
blotted out. The most careful scrutiny would tail 
t < > disclose them, where some time before they had been 
perfectly clear. And this though distance was at its 
minimum and definition at its best. Even the strongest 
marked of the strange pencil lines would show at times 
only as ghosts of their former selves, while for their more 
delicate companions it taxed one's faith to believe that 
they could ever really have existed. Illumination 
was invoked to account for this, and plays a part in the 
effect undoubtedly. x For at plumb opposition the cen- 
tre of the disk for two or three years has shown less 
detail than before and after that event. This is prob- 
ably due not, .as with the moon, to the withdrawal of 
shadows, but to the greater glare to which the disk 
is then subjected. But this is not the chief cause of 
the change. 

Still more striking and unaccountable was the fact 




Showing seasonal change. 

The increase of the 

that each canal had its own times and seasons for show- 
ing or remaining hid. Each had. its entrances upon the 
scene and its exits from it. 
What dated the one left 
another unaffected/) The 
Nilokeras was to be seen 
when the Chrysorrhoas was 
invisible, and the Jamuna 
perfectly evident when the 
Indus could scarcely be 
made out. 

So much shows in the two 
drawings here reproduced. 
Ganges and the advent of the Chrysorrhoas are 

noticeable in the second 
over the first. 

Seasonal changes seemed 
the only thing to account 
for the phenomena. And in 
a general sense this was 
undoubtedly the explana- 
tion. To learn more about 
the matter, to verify it if it 
existed, and to particularize 
it if possible, I determined to undertake an investiga- 
tion permitting of quantitative precision in the case. 
A method of doing this occurred to me which would 

Showing seasonal change. 

28(3 MARS AND ITS CANALS chap, xxm 

yield results deserving of consideration from the amount 
of data upon which each was based and capable 
of being compared with one another upon an equal 
footing from which relative information could be de- 
rived. It seemed wise to determine from the draw- 
ings the degree of visibility of a given canal at 
different seasons of the Martian year, and then to do 
this for every important canal during the same period 
of time. The great number of the drawings suggested 
this use to which they might be put. For from a great 
accumulation of data a set of statistics on the subject 
could be secured in which accident or bias would be 
largely eliminated and the telling effect of averages 
make itself felt. 

To render this possible it was necessary that the 
drawings should be alike numerous, consecutive, and 
extended in time. These conditions were fulfilled by 
the drawings made by me at the opposition of 1903. 
Three hundred and seventy-two drawings had then 
been secured, and they covered between them a period 
of six months and a half. They were also as consecu- 
tive as it was possible to secure. During a part of the 
period tin 4 planet was seen and drawn at every twenty- 
four hours, from April 5, namely, to May 26, or for forty- 
six consecutive days. Though the rest of the time did 
not equal this perfection, no great gap occurred, and 
one hundred and forty-three nights were utilized in all. 

chap, xxiii CANALS: KINEMATIC 287 

Furthermore, as these drawings were all made by one 
man, the personal equation of the observer a very 
important source of deviation where drawings are to 
be compared was eliminated. 

But even this does not give an idea of the mass of 
the data. For by the method employed about 
100 drawings were used in the case of each canal, 
and as 109 canals were examined this gave 10,900 
separate determinations upon which the ultimate 
result depended. That each of these determinations 
was independent of the others will appear from a 
description of the method itself on which the investiga- 
tion was conducted. To understand that method one 
must begin a little way back. 

As the two planets, Mars and the Earth, turn on their 
axes the parts of their surfaces they present to each 
other are constantly changing. For a feature on Mars 
to be visible from a given post on earth, observer and 
qbserved must confront each other, and, furthermore, 
it must be day there when it is night here. But, as 
Mars takes about forty minutes longer to turn than the 
Earth, such confronting occurs later and later each 
night by about forty minutes, until finally it does not 
occur at all while Mars is suitably above the horizon; 
then the feature passes from sight to remain hidden 
till the difference of the rotations brings it round into 
view again. There are thus times when a given region 

288 MARS AND ITS CANALS chap, xxm 

is visible, times when it is not, and these succeed each 
other in from five to six weeks, and are called presenta- 
tions. For about a fortnight at each presentation a 
region is centrally enough placed to be well seen; for 
the rest of the period either ill-placed or on the other 
side of the planet. 

If a marking were always salient enough it would 
appear in every drawing made of the disk during the 
recurrent fortnights of its display. If it were weaker 
than this, it might appear on some drawings and not on 
others, dependent upon its own strength and upon the 
definition at the moment, and we should have a certain 
percentage of visibility for it at that presentation. 
While if it changed in strength between one presentation 
and the next, the percentage of its recording would 
change likewise. Definition of course is always vary- 
ing, but if its value be noted at the time of each draw- 
ing this factor may be allowed for more or less success- 
fully. Making such allowance, together with other 
corrections to produce extrinsic equality, such as the 
planet's distance, which we need not enter upon here, 
we are left with only the marking's intrinsic visibility 
to affect the percentages; that is, the percentages tell 
of the changes it has successively undergone and give 
us a history of its wax and wane. 

From drawings accurately made it is possible to add 
to the accuracy of the percentage by noting in each, 

chap, xxin CANALS : KINEMATIC 289 

not only the presence or absence of the marking, but 
the degree of strength with which it is represented. 
This was done on the final investigation in the present 
case, and it was interesting to note how little difference 
it made in the result. 

The longitude of each canal was known, and the 
longitude of the central meridian of each drawing was 
always calculated and tabulated with the drawing, so 
that it was possible to tell which drawings might have 
shown the canal. Only when the position of the canal 
was within a certain number of degrees of the centre 
of the drawing (60) was the drawing used in the 
result, allowance being duly made for the loss upon the 
phase side. Each drawing, it should be remembered, 
was as nearly an instantaneous picture of the disk as 
possible. It covered only a few minutes of observa- 
tion, and was made practically as if the observer had 
never seen the planet before. In other words, the 
man was sunk in the manner. Such mental effacement 
is as vital to good observation as mental assertion is 
afterward to pregnant reasoning. For a man should 
be a machine in collecting his data, a mind in coordi- 
nating them. To reverse the process, as is sometimes 
done, is not conducive to science. 

When the successive true percentages of visibility 
of a given canal had thus been found, they were plotted 
vertically at points along a horizontal line correspond- 

290 MARS AND ITS CANALS chap, xxm 

ing in distance from the origin to the number of days 
after (or before) the summer solstice of the Martian 
northern hemisphere. The horizontal distance thus 
measured the time while the vertical height gave the 
relative visibility. The points so plotted were then 
joined by a smooth curve. This curve reproduced the 
continuous change in visibility undergone by the canal 
during the period under observation. It gave a 
graphic picture of the canal's change of state. It 
seemed, therefore, proper to call it the canal's cartouche 
or sign manual. 

In this manner were obtained the cartouches of 109 
canals)) Now, as the presence or absence of any canal 
in any drawing was entirely irrespective of the 
presence or absence of another, each such datum 
spoke only for itself, and was an entirely independent 
observation. The whole investigation thus rested on 
10,900 completely separate determinations, each as 
unconditioned by the others as if it existed alone. 

As every factor outside of the canal itself which could 
affect the latter 's visibility was taken account of, and 
the correction due to it as nearly as possible applied 
before the cartouches were deduced, the latter repre- 
sent the visibility of the canal due to intrinsic change 
alone. In other words, they give not the apparent only 
but the real history of the canal for the period con- 

chap, xxiii CANALS: KINEMATIC 291 

Important disclosures result from inspection of the 
cartouches. This we shall perceive by considering what 
different curves mean in the case. If the canal were 
an unchangeable phenomenon, for any reason what- 
ever, its cartouche would be a straight line parallel to 
the horizon of the diagram. This is evident from the 
fact that the visibility would then never vary. If, 
on the other hand, it were waxing and waning, and the 
wax or wane were uniform, the cartouche would be a 
straight line inclined to the horizontal; rising if the 
canal were increasing, falling when it decreased. 
Lastly, if the rate of change itself varied, the cartouche 
would be a curve concave or convex to the line denot- 
ing the time, according as the rate of change of the 
growth or decay grew greater or less. 

To see this the more clearly, we may set over against 
the cartouche the canal character it signalizes : 

Cartouche. Character. 

A horizontal straight line. Canal invariable. 

A straight line tilted up on the right. Canl increasing steadily. 

A straight line tilted up on the left. Canal decreasing steadily. 

A curved line descending, concave from Canal decreasing, but more 

above. and more slowly. 

A curved line ascending, concave from Canal increasing, but more 

above. and more rapidly. 

A curved line descending, convex from Canal decreasing more and 

above. more rapidly. 

A curved line ascending, convex from Canal increasing more and 

above. more slowly. 

292 MARS AND ITS CANALS chap, xsm 

Cartouche. Character. 

A curved line first descending, then Canal decreasing more and 
ascending, concave from above more slowly to a mini- 

throughout. mum, thence increasing 

more and more rapidly. 

A curved line first descending, then Canal increasing more and 

ascending, convex from above more slowly to a maxi- 

tliroughout. mum, thence decreasing 

more and more rapidly. 

If the cartouche first falls and then rises, this shows 
the canal to have passed through a minimum state at 
the time denoted by the point of inflection; if it rises 
first and falls afterward, this betokens in the same way 
a maximum. /Thus the cartouches reveal to us the 
complete history of the canals, what changes they 
underwent and the times at which these occurred. 
The cartouche, then, is the graphic portrayal of the 
canals behavior) It not only distinguishes at once 
between the dead and the living, as we may call the 
effect of intrinsic change, but it tells the exact character 
of this change, the way it varied from time to time, 
the epoch at which the development was at its minimum 
or its maximum for any given canal, and lastly, its 
actual strength at any time, thus giving its relative 
importance in the canal system. For the height of the 
curve above the diagrammatic horizon marks the abso- 
lute as well as the relative visibility and enables us -to 
rank the canals between themselves. 

Xow, the first point it furnishes a criterion for is the 

chap, xxm CANALS: KINEMATIC 293 

real or illusory character of the canals. If a line be due 
to illusion, whether optical or physical, it can vary only 
from extrinsic cause, since it has no intrinsic existence. 
If, therefore, all extrinsic cause be allowed for, the car- 
touche of this ghost must needs be a horizontal straight 
line. Even if the extrinsic factors to its production 
be imperfectly accounted for, their retention could only 
cause systematic variations from the straight line in all 
the lines, which would themselves vary systematically, 
and these factors could therefore be detected. 

This criterion is absolute. Unless all the cartouches 
were approximately straight lines, no illusion theory 
of any kind whatever could explain the facts. Even 
then the lines might all be real ; for unchangeable reality 
would produce the same effect on the cartouches as illu- 
sion. In the case therefore of horizontal straight line 
cartouches, we should have no guarantee on that score 
of reality or illusion ; but, on the other hand, curves or 
inclined straight lines in them would be instantly fatal 
to all illusion theories. . 

(Turning now to the 109 cartouches obtained in 1903, 
the first point to strike one's notice is that all but three 
of them are curves and that even these three must be 
accepted with a caveat. Here, then, the cartouches dis- 
pose once and for all of any and every illusion theory. 
They show conclusively that the canals are real objects 
which wax and wane from some intrinsic cause.^ 

294 MARS AND ITS CANALS chap, xxm 

The second result afforded by the cartouches is not of 
a destructive, negative character, however valuable 
the destruction of bars to knowledge may be, but of 
a constructive, positive one. It does not, like the first, 
follow from mere inspection, but is brought to light only 
by comparison of all the cartouches. In a positive way, 
t herefore, its testimony is as conclusive as it was in a neg- 
ative direction. For that 10,900 separate and independ- 
ent data should result in a general law of development 
through either conscious or unconscious bias, when those 
data would have to be combined in so complicated a 
manner for the result to emerge as is here the case, is 
impossible. Chance could not do it and consciousness 
would require a coordinate memory, to which Murphy's 
nine games of chess at once would be child's play. 

Of the 109 canals examined 106 showed by their car- 
touches that they had been during the whole or a part 
of the period in a state of change. But the change 
was not the same for all. In some the minimum came 
early; in others, late. Some decreased to nothing and 
staved there; others increased from zero and were 
increasing still at the time observations closecL) 

Latitude proved the means of bringing comparative 
order out of the chaos. When the canals were ranged 
according to their latitude on the planet, a law in their 
development came to light. To understand it, the 
circumstances under which the canals were presented 




must be considered as regards the then season of 
the planet's year. In 1903 the planet passed on 
February 28 through the point of its orbit where the 
summer solstice of the northern hemisphere occurs. 
One hundred and twenty-six days later took place the 
first snowfall in the arctic and subarctic regions, an 
event that denoted the beginning of the new polar cap ; 
from which date the snow there gradually increased. 
Its autumnal equinox the planet did not reach till 
August 29. Now, the canals were observed from thirty- 
six days before the summer solstice of the northern 
hemisphere to one hundred and forty-seven days after 
that event. We may tabulate the dates as follows : 

Day from 



Summer Solstice 


Date on Earth 



June 9 


June 22 

+ 30 


July 6 

+ 60 


July 20 

+ 90 


August 4 

+ 120 


August 20 

+ 150 


September 5 

The vernal longitude is the longitude of the planet 
in its orbit reckoned from the vernal equinox. From 
the table it appears that the cartouches cover the de- 
velopment of the canals from about June 6 to September 
1 of the Martian northern hemisphere for the current 
but to us undated year, ab Marie condita. 




The 109 canals included all the more conspicuous 
canals on the planet at that opposition, all those 
that lent themselves by the sufficient frequency 
with which they were seen to a statistical result. 
They lay spread all the way between the edge of 
the polar cap in latitude 87 north to the extreme 
limit south, at which the then tilt of the north pole 
toward the earth permitted of canal recognition. 
This southern limit was in about latitude 35 south. 
Farther south than this vision became too oblique, 
amounting as it did, with an adverse tilt of twenty- 
five degrees to start with, to something over sixty 
degrees, for detection of such fine markings to be 
possible. Between the two limits thus imposed, by 
the perpetual snow on the one side and the ob- 
servational tilt on the other, the 109 canals were 
distributed by zones as follows: 





North Polar 

87 N.-78 N. 



78 X.-6(> X. 



6GX.-f)l N. 


North Temperate 

51 N.-37 N. 


North Sub-Tropic 

37N.-24 V 


North Tropic 

24N.-12 N. 


North Equatorial 

12 X.- N. 


South Equatorial 

X.-12 S. 


South Tropic 

12 S.-24S. 


South Sub-Tropic 

24 S.-37S. 


chap, xxm CANALS: KINEMATIC 297 

As the latitude of a canal in the investigation was 
taken as that of its mid-point, such being the mean 
value of its successive parts, the latitudes about which 
information was obtained lay within the limits given 
above, the most northern canal, the Jaxartes N having 
for its mid-latitude 78 north, and the most southern, 
the Nectar, that of 27 south. 

The zones comprised each a belt of territory about 
thirteen degrees wide, the first being less solely because 
in part occupied by the permanent polar cap. 

The curves of all the canals in a given zone have been 
combined into a mean curve or cartouche for that 
zone; and then the cartouches for the several zones 
have been represented and ranged according to lati- 
tude on the accompanying plate. Consideration of 
these mean canal cartouches is very instructive. In 
the first place not one of them is a straight line, either 
horizontal or inclined. All are curves and, with the 
exception of the top one, all show a minimum or lowest 
point during the period under observation. From this 
point they rise with the time, or to the right on the 
plate. A black star marks this minimum, and is found 
farther and farther to the right as one goes down the 
plate ; that is, as one travels from the neighborhood of 
the arctic regions down to the equator and then over 
into the planet's southern hemisphere. Drawing now 
a line approximately through the stars and remembering 


< IIAI'. Will 



N Polar 


Mean Lat.5e o N 

MeanLat. 44 e N. 
AC TentfiertUc 

Mean Lat.ji'N. 
N. Sub-Tropic 

MeanLat kj-N. 
N. Tropic 

MeanLat. 6*N. 

S. Equatorial 

MeanLat. i8*S. 
S. Trophic 

MeanLat 26*S. 

*- Minimum vi.ibilfty MEAN CANAL CARTOUCHES 


chap, xxin CANALS : KINEMATIC 299 

that the minimum means the date at which the canal 
started to develop, we see that [the canal development 
began at the border of the north polar cap and thence 
continued down the disk over the planet's surface, as 
far as observation permitted the surface to be seen, 
which was some thirty-five degrees into the other hemi- 
sphere. This is the first broad fact disclosed by the 

^Furthermore, the development took place at an 
approximately uniform ratej This is shown by the 
fact that the line passing through the black stars is 
approximately straight; for such straightness means 
that progression down the disk as measured by the 
latitude bore throughout the same ratio to the time 

Looking at them again we notice that the three top- 
most cartouches, those of the north polar, arctic, and 
sub-arctic canals respectively, dip at the right before 
the end of the observations, while the other seven were 
still rising when those observations were brought to a 
close. A reason for this, or at least a significant coin- 
cidence, is to be found in the dotted line pendent from 
the top of the table and labelled " First Frosts." This 
dotted line denotes the date at which the first extensive 
frost occurred in the polar regions; for even before 
this time patches of white had appeared north of the 
Mare Acidalium, denoting the on-coming of the cold. 

300 MARS AND ITS CANALS cm*, xxm 

The frost did not last but came and went and came 
again just as it does on earth, growing more insistent 
and long-lived at each fresh fall. Its sphere of opera- 
tion was confined to the three zones in question. 
Even these zones it by no means covered, merely 
I Notching them in places with fungi-like patches of frost. 
Beyond them south it never extended during the period 
of the observations ; indeed, it hardly entered the sub- 
arctic zone at all at this very beginning of the polar 
winter. For it was only August 20 then. The coin- 
cidence of the isotherm as betrayed by the deposition 
of frost with the dividing line between the canal- 
development curves that dip down at this season and 
those that still continue to rise is suggestive. 

It becomes all the more so when the three cartouches 
are considered seriatim. The most polewards, the 
north polar one, had sunk to zero sometime before the 
first extensive frost occurred; the second, the arctic, 
did so later than its northern neighbor, probably just 
before the epoch in question; while the third, prac- 
tically outside the zone of deposition, was behind both 
the others in its descent. (Jnspection of the drawings 
upon which the cartouches are based confirms an infer- 
ence deduced from this: that it was cold that killed, 
not frost that covered, them, which was responsible 
for their obliteration. The drawings show that the 
canals ceased to be seen before the white patches were 

chap, xxm CANALS: KINEMATIC 301 

evident. Now this would be the exact behavior of 
vegetation. It would be killed, turned brown by 
freezing, and so rendered invisible to us against its 
ochre desert background, before the cold had grown 
intense enough to cover that ground with a solid white 
carpet of frost. At the opposition of 1905, however, 
the extreme northern canals were visible after the snow 
had covered all the country about them, being evident 
as lines threading the new cap. 
/These three cartouches furthermore show each a 
maximum, and what is significant the maximum occurs 
later in time for each, according as the zone lies remote 
from the pole. A red star marks this maximum and 
shows that the time of greatest development for the 
three zones was respectively : 

41 days after the summer solstice for the North Polar. 

61 days after the summer solstice for the Arctic. 

95 days after the summer solstice for the Sub-Arctic. 

We now pass to the other curves, those that were 
unaffected by cold. Though in these the minima them- 
selves show the law of latitudinal progression, the wave- 
like character of the advance is even better disclosed 
by the curves. As the eye follows them down the 
page, the advance of the wave to the right is plainly 
apparent. The slope of the wave is much the same for 
all, implying that a like force was at work successively 
down the latitudes. 

302 MARS AND ITS CANALS chap, xxih 

( It will bo noticed next that in all the mean car- 
touches the gradient is greater after the minimum 
than before it. The curves fall gently to their lowest 
points and rise more steeply from them. Such profile 
indicates that the effects of a previous force were slowly 
dying out down to the minimum and that then an im- 
pulse started in to act afreslu This explains the atti- 
tude of the canals that died out. In them the effect 
of the old force shows as in the others, but no impulse 
came in their case to resuscitation. 

It seems possible to trace this force to an origin at 
the south. For beginning with the north sub- tropic 
zone the gradient on the left shows less and less steep 
southward to the south sub-tropic zone. Such a 
dying-down swell is what should be looked for in an 
impulse which had travelled from the south northward, 
since the wave would affect the more northern zones 
last, and less of a calm period would intervene between 
the two impulses from opposite poles. 

The cart ouches, then, state that the canals began to 
develop after the greatest melting of the polar cap 
had occurred; that this development proceeded down 
the latitudes to the equator, and then not stopping 
there advanced up the latitudes of the other hemi- 
sphere. In the next place they show that in the 
arctic region the development was arrested and devo- 
lution or deeay set in as it began to get cold there, 

chap, xxiii CANALS: KINEMATIC 303 

the most northern canals being affected first. Finally, 
that a similar wave of evolution had occurred from 
the opposite pole some time before and had then 
passed away. And this evidence of the cartouches 
is direct, and independent of any theory. j 




Individually Instanced 

S an interesting instance of the law of develop- 
ment we may take the career of the Brontes 
during this same Martian year; the Brontes witness- 
ing individually to the same evolutionary process that 
the canals collectively exhibit. 

The Brontes is one of the most imposing canals upon 
the planet. It is not so much its length which renders 
it a striking object, though this length is enough to 
entitle it to consideration, being no less than 2440 miles. 
Its direction is what singles it out to notice, for it runs 
almost north and south. For this reason it swings into 
a i >< >sition to hold the centre of the stage for a time with 
the | decision of a meridian, as the planet's rotation 
turns its longitude into view. The points which it 
connects help also to add to its distinction. For the 
Sinus Titanum at its southern end and the Propontis 
at its northern are both among the conspicuous points 
of the disk. The latter is but twelve degrees farther 
east than the former, while it is sixty-six degrees farther 
north. This longdistance, from nearly the line of the 
tropics in the southern hemisphere to mid-temperate 


chap, xxiv CANAL DEVELOPMENT 305 

regions of the northern, the canal runs in an 
absolutely straight course. 

Its north and south character commends it for any 
investigation of canal development, since it runs in the 
general direction that development takes. Its great 
latitudinal stretch further fits it for a recorder of 
changes sweeping down the disk; so that both in di- 
rection and length it stands well circumstanced for a 
measure of latitudinal variations. The fact that it is 
usually a fairly conspicuous canal does not detract from 
its virtue in this respect. It was first recognized at 
Flagstaff in 1894. But once realized, so to speak, it was 
possible to identify it with a canal seen by Schiaparelli 
and supposed by him to be the Titan ; indeed, it played 
hide and seek with that canal throughout his drawings. 
In 1894 both it and the Titan were so well seen that its 
separate existence was unmistakable, causing it to be 
both recognized and named. It is, like the Titan, one 
of the sheaf of canals descending the disk from the 
Sinus Titanum, and lies just to the east of the Titan in 
the bunch. In 1896 it was also prominent; and at 
both these oppositions most so from its southern end, 
its northern one being more or less indefinite, especially 
in 1894. 

In 1901 it was not the same. Instead of being the 
conspicuous canal it had been in earlier years, it was 
now so faint as with difficulty to be made out. It 

306 MARS AND ITS CANALS chap, xxiv 

remained so to the close of observations. It was now 
under e pieiorv Its behavior in 1896-1897 had led 
to the supposition that not only were seasonal changes 
taking place in it, but that those changes were such as 
to point to a law in the case with which its conduct in 
1901 fayed in. The suspicion did not, however, be- 
come a certainty till the opposition of 1903. The length 
of time during which the disk was then kept under scru- 
tiny resulted in the method of its metamorphosis being 

At the very start of observations its longitude chanced 
to be nearly central and it was made out; but so far off 

was the planet that only its 

y<^^k > northern part could be de- 

/, ' v\ tected, because, as after- 

# \ ward appeared, this part 

] was the stronger, the canal 

/ being decidedly inconspicu- 

\ / ous, whereas other canals, 

/ the northern and even the 

^-du-*' Pallene and the Dis, were 

L Februar y 2B - strongly marked. At the 

next presentation the planet was nearer, and detail* 

previously hidden for the distance now came out. 

Among them was the Brontes, which, showing better 

than in January, could be traced all the way to the 

Sinus Titanum. A drawing (I) made on February 25 




II. March 30. 

and reproduced in the text shows its appearance at 

the time. Its emergence under neared conditions 

only served to accentuate 

its relative inconspicuous- 

ness, for it showed now 

notably inferior to the 

northern canals, and this 

not only in the matter of 

general visibility, but in 

the character it displayed. 

It was a line of hazy defi- 
nition, contrasting thus 

with the sharp dark forms of its northern neighbors. 
As the planet steadily approached the earth, and the 

canals to the north became 
better and better seen, the 
Brontes instead of sharing 
in the general improve- 
ment did exactly the op- 
posite. It grew less visible 
when it should have grown 
more so, if distance had 
been the cause of its ap- 
pearance. It was now 

only to be seen at the north, even when it was seen 

at all; a state of things exemplified in Drawings II 

and III. 

III. April 3. 




IV. May 4. 

As t> planet now went away ; d u 1 should have 
dr es } roceeded i Jic opposite. One 

ha a i it was ac c dated by a spirit of con- 

trariety. For now when it 
had reason to grow faint 
it grew in conspicuous- 
ness ; just as, before, when 
it should have become evi- 
dent, it had declined. Dis- 
tinctly farther off and 
smaller as the planet was 
at the next presentation, 
the Brontes had clearly 
developed both in tone and in the amount of it visible. 
This was in May (Drawings IV and V). In June bad 
seeing prevented good ob- 
servations, but in July, 
Drawing VI, when the re- 
gion again came round, the 
Brontes, in spite of the then 
greatly increased distance, 
asserted itself so strongly 
that even in not very good 
seeing its presence could 
not be passed by. 

This contrariety of behavior had about it one very 
telling feature. That the canal waxed or waned in exact 

May 7. 




opposition to distance and even toward the last to see- 
ing too, showed conclusively that neither distance nor 
definition could in any way be held responsible for its 
metamorphoses. A very fortunate circumstance, this of 
the observations, for it directly eliminated size of disk, 
phase, and seeing, for which correction are none too easy 
to make, and which in the minds of the sceptical could 
always remain as unex- 
plained possibilities of error. 
The mean-canal car- 
touches show synthetically, 
and all the more conclu- 
sively for being composite, 
the laws of the flux of the 
canals. Something more of 
vividness, however, is im- 
parted by the actual look of 
one of the constituents during the process. It is the 
difference between seeing a composite picture made 
from a given group of men and the gazing on the actual 
features of any one of them. So much is gained by the 
drawings across the page of the Brontes at different 
stages of its evolution during the period here concerned. 
But in another way, too, the one canal may be made to 
yield a more lifelike representation of the process than 
a number taken together are capable of affording. In 
the mean-canal cartouches each canal is treated as an 

VI. July 18. 




entity; but it is possible to consider a canal by parts, 
and by so doing to see it in action, as it were. It 
occurred to me to treat the Brontes in this way. For 
this purpose I divided the canal into sections, five of 
them in all, between the point where it left the Pro- 
po ntis, at a spot called the Propropontis, to where it 
ended in the Sinus Titanum. The first, the most 
northern, extended as far as Semnon Lucus, the south- 
ernmost outpost of the Propontis congeries of spots. 
The second continued on from these to Eleon, the 
junction where the Erebus crossed. The third thence 
to Utopia, where the canal met the Orcus ; the fourth 
to an arbitrary point in latitude 8 south, and the fifth 
and last to the Sinus Titanum. The lengths of these 
sections were respectively: 12, 16, 15, 12, and 13. 
Each of the sections was then treated as if it were a 
separate canal and its cartouche found. To the car- 
touches' determination there were available drawings: 

January 21-25 
February 23-March 2 
March 28-April 5 
April 20- May 8 . 
June 3-16 . 
July 11-21 . 

12 drawings. 

15 drawings. 
14 drawings. 
27 drawings. 

( drawings. 

16 drawings. 

90 drawings in all. 

The cartouches are given in the plate opposite, 
which is constructed precisely like the one for the mean 




canal cartouches presented on page 298. The mid-lati- 
tude of the section and its mid-longitude are given in 
the margin with its description. 

(Examining them now we note a family resemblance 
between the successive cartouches. All sink slowly 

on the left to rise sharply from their lowest point to the 
right. Such resemblance betokens the action of one 
and the same cause. 

Next, although the curves are resemblant, each has 
been, as it were, sheered to the right as one reads down : 
that is, the action took place later and later as the 
latitude was north. 

Lastly, the dying out of a previous impulse can be 

312 MARS AND ITS CANALS chap, xxiv 

traced in the cartouches, which shows that the canals 
were quickened six months previously from the south 
polar cap, as they were now being quickened from the 
north polar one. 



/CONNECTED with the conduct of the canals is a 
phenomenon, examples of which were early noted 
in a general way by Schiaparelli and later, but of 
which the full import and exhibition only came to light 
during the opposition of 1903 by a very striking meta- 
morphosis: what may be called the hibernation of a 
canal for a longer or shorter term of years. What 
observation discloses is certainly curious. For several 
successive oppositions a canal will be seen in a definite 
locality, as regular in seasonal recurrence as it is per- 
manent in place, a well-recognized feature of the disk. 
Then to one's surprise, with the next return of the 
planet, it will fail to appear, and will proceed to remain 
obliterate without assignable cause for many Martian 
years, until as unexpectedly it will be found what and 
where it was before. Neither to deposition of hoar- 
frost, such as frequently whitens whole regions of Mars, 
nor to other circumstances can be attributed its dis- 
appearance. Without apparent reason it simply ceases 
to be and then as simply comes back agaim\ 


314 MARS AND ITS CANALS chai- ui 

Such bopeep behavior is quite beyond and apart 
from the seasonal change in visibility, to which all the 
canals arc by their nature subject. For being creatures 
of the semi-annual unlocking of the water congealed 
about the polar caps, they quicken into growth and 
visibility, each in its season, and as regularly die out 
again. Different, however, is the phenomenon to 
which I now refer. In it not a seasonal but a secular 
change is concerned. The season proper to the canal's 
increase will recur in due course, and the canals round 
about it will start to life, yet the canal remains unquick- 
ened. Nothing responds where in years the response 
was immediate and invariable. The canal lies dormant 
spite of seasonal solicitation to stir. 

Such curious hibernation was early hinted to the 
keenness of Schiaparelli, and most incomprehensible as 
well as difficult of verification at that stage the phe- 
nomenon was. That the absence was a fact, however, 
he assured himself, although he was not able to prove 
an alibi. But at the last opposition an event of the 
sort occurred which, from the length of time the planet 
was kept under observation, combined with continued 
suitableness of the seeing, unmasked the process. In 
the light of what then happened, taken in connection 
with the side-lights thrown upon it by the canal's past 
and by the knowledge we have meanwhile gained of the 
planet's physical condition, the riddle of the phenome- 


non may in part at least be read, and most interesting 
and instructive the reading proves to be. 

Among the initial canals detected by Schiaparelli, 
in 1877, was a tricrural set of lines recalling the heraldic 
design of three flexed legs joined equiangularly above 
the knees. It lay to the east of the Syrtis Major, and 
he called its three members the Thoth, the Triton, and 
the Nepenthes. Starting from the head of his gulf 
of Alcyonius, at a point now known to be occupied by 
the oasis called Aquae Calidae, the Thoth started 
south inclining westward as it went, till in longitude 
267 and latitude 15 north, it met the Triton, which 
had come from the Syrtis Minor with similar westward 
inclination. To the same point in the same manner 
came the Nepenthes. Part way along the course of the 
latter was to be seen a small dark spot, the Lucus 
Moeris, which he estimated at four degrees in diameter. 
Some of the markings were easier than others, the 
easiest of all being the Lucus Tritonis, a largish dark 
spot at the common intersection of all three canals; 
but that none of the markings were remarkably diffi- 
cult is sufficiently shown by their detection at this early 
stage of Schiaparelli's observations. It is worth noting 
also that he discovered the southern ones first; the 
Thoth not being seen till March, 1878. As his then 
recognition of these canals witnesses, they must have 
been among the most evident on the disk. And the 

316 MARS AND ITS CANALS chap.mct 

point is emphasized by the fact that he failed at this 
opposition to detect the Phison and the Euphrates 
as separate markings. 

Much the same the three canals appeared to him at 
the next opposition of 1879, the Thoth being seen at its 
several presentations from October 5, 1879, to January 
11, 1880. 

At the next opposition a noteworthy alteration 
occurred, the full significance of which escaped recog- 
nition. Schiaparelli saw, at the place where the Thoth 
had been, two lines which he took for a gemination of 
that canal, one of which followed the course of the old 
Thoth, while the other went straight from the Sinus 
Alcyonius to the Little Syrtis, or, more precisely, to the 
junction of the Triton and the Lethes. It was not the 
Thoth, however, but something unsuspected, of more 

In 1884 the Thoth showed really double, the western 
line being much the stronger, "una delle piu grosse 
linee que si vedessero sul disco." That neither branch 
went farther than the meeting-place with the Nepen- 
thes argues that it was indeed the Thoth that was seen. 
Schiaparelli himself had no doubt on the subject, al- 
though he drew the double canal he saw due north and 
south from the tip of the Sinus Alcyonius to the junc- 
tion, hut nevertheless along the 263 meridian. 

In 1886 and 1888 the system was in all essentials, 



what it had been in 1877 and 1879, except that the 
Thoth and Nepenthes were double and were more 
minutely seen. 

Here, then, was a system of canals and spots which 
for six Martian years had been a persistent and sub- 
stantially invariable feature of the Martian surface. 
Any changes in it had been of a secondary order of im- 
portance, while its general visibility was of the first. 
It is possible, then, to judge of my perplexity when in 
beginning my observations in 1894 no sign of the system 
could I detect. Of neither the Thoth, the Triton, the 
Nepenthes, nor the Lucus Moeris was there trace. And 
yet, from the other canals visible, it was evident that 
the disk was quite as well seen as it had been by Schia- 
parelli. Not only were practically all his canals there, 
but many much smaller ones were to be made out. 
And the same was true of the spots, a host of such not 
figured by him appearing here and there over the 
planet's surface. 

Nor was this all. Instead of the Thoth, another canal 
showed straight down the disk from the Syrtis Minor 
to the Aquae Calidae. This canal was as unmistakable 
as the Thoth had been before to Schiaparelli. It was 
among the first to be detected, and continued no less 
conspicuous to the end, the dates at which it was seen 
being July 10, August 14, and October 21. I called it 
the Amenthes, identifying it with the canal so named 

318 MARS AND ITS CANALS chap, x.w 

in Schiaparelli's chart published in Himmel und 
Erde, of the ensemble of his observations from 1877 to 
L888. But in his Memoirs he never called it so, seeing 
it, indeed, only in 1881-1882, and deeming it then the 
Thoth. Nevertheless, in 1894, it was the conspicuous 
canal of the region, and, what is more, had come, as 
it proved, to stay. 

The invisibility of the Thoth continued for me the 
same during the succeeding oppositions of 1896-1897 
and 1901. At the former opposition I drew it in 1896 
on July 28, August 26, September 2, October 5-9, 
seeing it single; and in 1897 on January 12-19, Febru- 
ary 21, and March 1. It was single but with suspicions 
of doubling in January, and was indubitably double in 
February. As for the Thoth, I had come to consider 
it and the Amenthes one, attributing their diversity 
of depiction to errors in drawing. For while the Thoth 
remained obstinately invisible, the Amenthes presented 
itself as substitute so insistently as to make one of the 
most obvious canals upon the disk. 

One exception only was there to this state of things. 
On June 10, 1901, my notes contain this adumbration 
of a something else: " Amenthes sometimes appeared 
with a turn to it two-thirds way up; two canals con- 
cave to the Syrtis Major." 

So matters opened at the opposition of 1903. With 
the advent of the planet and the presentation in due 



Amenthes alone in February. 

course of Libya in February, the Amenthes duly ap- 
peared, much as it had showed at the opposition before, 
only less salient. It was a 
confused and seemingly nar- 
rower double. Suspected 
on the 16th of that month, 
it was definitely seen from 
the 18th to the 23d. Of 
the Thoth no mention is 
made either in the notes or 
in the drawings. When the 
region came round again, in 

March, the Amenthes was still there, showing more 
feebly, however, than it had in February, in spite of 

better seeing and the fact 
..^^u that the planet had consid- 

erably neared. Clearly the 
canal was fading out ; a fact 
further witnessed to by the 
following note made on 
March 25: "Throughout 
this opposition thus far the 
dark triangle tipped by 
Aquae Calidae has been 
sharply divided in intensity from the Amenthes, which 
is very narrow and exceedingly faint." Still was 
there no trace of the Thoth. 


Amenthes feebler and still alone 
in March. 



( IIA1-. A.W 

With the April presentation entered a new order of 
things. When the region first became visible, on the 
10th, the Amenthes could still be seen and alone; 
but on the 19th, as the relative falling back of the Mar- 
tian longitudes swung the 
region nearer the centre of 
the disk, the Thoth appeared 
alongside of it. On the 
20th the Thoth showed 
alone. Unmistakable it was 
and just as Schiaparelli had 
drawn it, accompanied by 
the Triton and the curved 
Nepenthes. The thing was 
a revelation. What before I 
had seen only in the spirit of another's drawings stood 
there patent to me in the body of my own; while the 
Amenthes, to which I had so long been accustomed, 
had vanished into thin air. Only a trace of it was 
now and then to be made out. So startlingly strange 
was the metamorphosis that I could not at first trust 
my eyes, and questioned the broken line, which had 
replaced the straight, for some ocular deception. But 
nothing I could do would rectify it. The Amenthes 
was gone and the Thoth stood in its stead. 

At the next presentation, May 26 to June 8, the 
phenomena were repeated, and with increasing clarity. 

Appearance of Thoth with Tri- 
ton and curved Nepenthes. 
Amenthes vanished. April 20. 





And then of a sudden , on May 29, I saw the long- 
given-up Lucus Moeris. There it was indubitably. 
And its definiteness was the most astonishing part of 
the affair. It was no question of difficult detection. 
Indeed, I had not been on the lookout for it, having 

searched the region too often . 

fruitlessly before to have 
left incentive to search again. 
And so, when I was not 
searching, the thing of its 
own accord stepped forth 
to sight. It was a small 
round dot, like to any other 
oasis, and showed, as it were, 
a black pearl pendent by 
the Nepenthes from the Syrtis's ear. For the Libyan 
bay made a dark projection of the sort high up on the 
Syrtis's eastern side, from which the Nepenthes, pre- 
cisely as Schiaparelli had drawn it, curved down to the 
point where the Thoth and Triton met. All three 
canals were geminated, the gemination being about 
three degrees wide. 

And now occurred the last act in the drama. In 
July the Amenthes reappeared, showing alongside of 
,the Thoth-Nepenthes, and thus removing any possible 
doubt as to their separate identity. It had, indeed, 
become the stronger of the two, having gained in 

Advent of the Lucus Moeris. 
May 29. 




strength in the interval between June and July and 
the Thoth-Nepenthes having lost. The lines were in 
process of relapsing into the status quo ante. Had 
these three presentations not been watched, the brief 
apparition of the Thoth-Nepenthes had been missed 

and with it the revealing of 
its curious character, and 
of certain deductions there- 

First among these is a 
truth of which I have long 
been convinced ; to wit, that 
when a seeming discordance 
arises between the portrayals 
of a canal, it is commonly 
not a case of mistake nor of change, but one of separate 
identity. The canal has not shifted its place, nor has 
an error been committed; the fact is that one canal 
has been observed at one time, another at another. 

So it was here, and thus were the old and the new 
observations reconciled. There had been no mist .ike 
in either. Two separate canals accounted for the dis- 
crepancy, and only an unfounded distrust of the accu- 
racy possible in such observations was to blame for 
any failure to recognize the fact. 

X( >w, scrutiny of the notes upon the appearance of the 
two canals, together with their labeling by the seasonal 

Amenthea with Tin >th- Nepenthes 



longitudes of the planet at the dates they were made, 
discloses a curious relation between the two. The 
seasonal longitudes are important, as they date the 
phenomena according to the Martian calendar. Or- 
dered thus, the successive aspects reveal first a seasonal 
change in each canal and then over and above this a 





secular one. And this secular change was such as to 
cause the two canals to alternate in visibility. When 
the one was present the other was not, and vice 


We shall see this more clearly and at the same time 
bring out a curious relation between the two systems, 
the broken bow of the Thoth-Nepenthes-Triton and the 
straight arrow of the Amenthes, while looking at the 

324 MARS AND ITS CANALS chap, an 

cartouches of the Thoth, the Amenthes, and a combi- 
nation of both given in the plate on previous page. 

The antithetical character of the two canals is appar- 
ent. But what is further interesting, the combination 
cartouche of both bears a singular resemblance to that 
of the mean canal of the north tropic zone, the zone 
to which both canals belong. . Here, then, is a combi- 
nation which is perfectly regular while each of its con- 
stituents is anomalous. 

And now we come to something as important: at 
the opposition of 1905 the curious alternation meta- 
morphosis was enacted anew. The Amenthes appeared , 
disappeared to be replaced by the Thoth, and then re- 
appeared again beside the other. This corroboration 
of behavior showed the previous observations to have 
been due to no mistake, and only served to deepen the 
interest in this last and more singular phase of canal 



AST in time but not least in importance of the 
details of canal development to be detected is one 
that connects these strange features directly with the 
melting of the polar caps. The cartouches showed 
that such connection was to be inferred ; the facts now 
to be recorded depict it by an identity of place between 
certain phenomena of the two subjects following one 
another in order of time. 

On January 8, 1897, while scanning the planet, I 
was suddenly ware of a rift in the north polar cap. It 
ran a little to the west of south from where it started 
in at the cap's edge and went clean through to the limb, 
the pole being then slightly tilted away from us. At the 
time it seemed to be the first rift ever seen in that 
cap ; but on opening a little later Schiaparelli's Memoria 
Quarta, which had just arrived, the first thing my eye 
fell on was a drawing of a rift in the north polar cap 
observed by him when the planet had held the like 
attitude toward the Earth thirteen years before. Ref- 
erence to its longitude showed it to be the identical 


326 MARS AND ITS CANALS chap, xxvi 

rift, seen again after all these years and the only one 
so far seen in the northern cap. 

At the next opposition more rifts were detected, one 
in especial on December 27, running from Arethusa 
Lucus, then upon the edge of the cap, athwart the 
snow in a northwesterly direction. 

In the forepart of the opposition of 1901, which in its 
Martian season corresponded to that in 1897, when the 
rift had been observed, many rifts were detected in the 
cap, and among them one traversing the cap north- 
northeasterly in longitude 136. 

So far the season when the cap had been observed 
was that when the rifts were in process of forming. 
The ground they and the snow-cap covered had not yet 
at any opposition been uncovered. 

It was only when my observations began in the 
Litter half of the opposition of 1901 that, the season on 
Mars having so far advanced, all snow in those latitudes 
had melted. Then appeared, however, the canal 
Hippalus, an arctic canal of some importance, lying 
on that part of the planet previously occupied by the 
polar cap. When later studying the observations 
on the rifts I remembered this canal, and turning 
to the (hawing made some months before to compare 
the two critically, discovered that the canal occupied 
the precise position held earlier by the rift. One had 
said the rift had never vanished, but that the white 




surrounding it had simply turned to ochre. Here, 
then, was a striking coincidence of place, too exact to 
be the result of chance. 

Impressed by the identity, I examined all the other 
rifts seen early in 1901, comparing them with the arctic 
canals seen later, to the finding of no less than five cases 
of the same coinciding positions. 

The importance of the identification here made of an 
arctic canal with a previous rift in the polar cap has 
led me to make a list of the canals thus identified at 
this opposition. 

Visible as a Rift 

Visible as a Canal 


January 1 and February 4 

April 18 (?), May 20,22, 
27, June 4, 5, 6, 7, 8, 25 


January 19 and February 4 

April 18, May 27 


February 4 

May 27 


February 20 

March 31 


January 18, 19 

May 7, June 3 to 8 

If it be asked why these canals do not appear recorded 
at the March presentation as either the one phenomenon 
or the other, the answer is twofold. First, because they 
showed as shadings lost amidst a shaded mass; and, 
secondly, the observations at several oppositions indi- 
cate a great amount of haze over the region at that 
season of the Martian year. 

We may now go back to the very first rift, that of 
1897. The Martian season grew later with each sue- 


ceeding opposition, and it so chanced, abetted by this 
fact, that the delaying snow was never seen covering 
that part of the planet again and so, of course, not 
the rift. The Martian summer in those high lati- 
tudes came on, and with it brought the great arctic 
canal, the Jaxartes, into conspicuousness. The canal 
in consequence had been observed for some time 
before it proclaimed itself the apotheosis of a rift 
and that of the first and most important rift of all. 
Comparison of position, however, entirely confirmed 
the conjecture and added another and the most 
striking of all to the list. 

CThese six canals, on the whole the largest which run 
into the northern cap, have thus a dual character. 
Starting originally as rifts, they later come out un- 
mistakably as canals. So that we may say in general 
thai the two phenomena are different seasonal states 
of the same thing) This instantly explains the rifts, 
the origin of which we found of so difficult, not to say 
impossible, interpretation before in these pages, and 
incidentally it confirms what we deduced on other 
grounds as the character of the canals; to wit, (strips 
of vegetation. For if the cap covered desert and 
fertility alike, it is precisely over the latter that it 
would first melt) 

Vegetation has the property of melting snow. Hie 
metabolism of the plant, like that of the animal, though 

chap, xxvi CANALS AND KIFTS 329 

in a less degree, generates caloric. A living animal is 
warm, even the so-called cold-blooded ones, in some 
sort, and a growing plant is too. The chemic processes 
concerned give off heat, though in such small quantities 
that we are often not aware of it. While the plant lies 
dormant it stays cold, but the moment its sap begins 
to run under the rays of the spring sun it rises in 
temperature above its winter surroundings. All it 
needs to this awakening is sun and water, and both it 
gets in its place in the polar cap after the passing of the 
vernal equinox. The time, therefore, is suitable, for 
it is not till after that equinox is passed that any of the 
above phenomena occur. In consequence the snow 
about it melts and the plants themselves show as 
dark rifts splitting the cam 

This quite unexpected identity of two seemingly 
diverse phenomena, and the unsolicited support its 
only explanation lends to the general theory, is an 
instance of what is constantly occurring as observa- 
tion of the planet is pushed farther and farther. Facts 
every little while arise which prove to fit into place in 
the scheme when neither the facts nor their fitness 
could have been foreseen. 


oases; kinematic 

jO UB JECT to change also are the oases ; and in the 
same manner apparently as the canals. They 
grow less evident at a like season of the Martian year. 
They do this seemingly by decreasing in size. Whereas 
in the full expanse of their maturity they show as 
round spots of appreciable diameter, as the season 
wanes they contract to the smallest discernible of dots^ 
All but the kernel, as it were, fades out, and even this 
may disappear from sight. The Phcenix Lake in 
its summer time is a very dark circular spot, small 
indeed yet of definite extension ; in its winter it shrinks 
to a pin point, and is often not visible at all. Some- 
times the husk apparently persists, a ghostlike remi- 
niscence of what it was, with the kernel showing dark- 
pointed in its centre. Thus the Lucus Lunae appeared 
at the opposition of 1905. A faint wash betokened the 
presence of the Lucus, through which now and again 
a black pin-point pierced. 

In this visible decrease of size we get a revelation as 
to what takes place impossible in the case of the canals, 


chap, xxvii OASES 5 KINEMATIC 331 

the tenuous character of which precludes more than 
inference as to the process. 

/Like the canals, latitude, together with the suitable 
season of the planet's year, are the determining factors 
in their development. In what corresponded to our 
July of the northern hemisphere the oases in the 
sub-arctic and north temperate zones were conspicu- 
ous; black spots that showed in profusion along the 
parallels of 40, 50, and 60 north. At the same 
time the equatorial ones, those along the Eumenides- 
Orcus, which had been most evident in 1894, hardly 
came out.) It had been their time then as it was that 
of the others now. The law of development is not so 
simple as on the earth, depending, like that of the 
canals, not only upon the return of the sun, but upon 
the advent of the water let loose from about the 
polar caps. Thus the equatorial oases are subject to 
two seasonal quickenings, one from the north, the 
other from the south) 

In regard to their method of evolution or devolution 
a most curious observation happened to me in 1903. 
Usually the oases are of solid tone throughout ; equally 
sombre from centre to circumference. But in this 
case such uniform complexion found exception. On 
March 1, 1903, the Ascraeus Lucus came out strangely 
differentiated, a dark rim inclosing a less dark kernel. 
The sight was odd enough to command comment in the 

332 MARS AND ITS CANALS chap, xxvn 

shape of a sketch which accompanied the note, and the 
further remark that other spots had similarly that year 
affected the like look. That the effect was optical did 
not seem to me the case. Other spots at other times 
showed nothing of the sort. If it was due to objective 
cause it gathers circumstance from what was then the 
Martian time of year. For the season was such that 
the spot should then have been in process of waning; 
and the effect would indicate that in so doing the tone 
of the centre went first, that of the circumference fading 
last. This would be in accordance with a growth 
proceeding outward and a decay that followed in its 


(When to this we add the look of the oases at the 
antithetic season, often a faint shading only, with or 
without a darker pin-point at its core, we are led 
to the belief that the area of the oasis is unchangeable 
and that its growth means a deepening of tini> 

So far, then, as it is possible to particularize them, 
the oases develop from a small nucleus, perhaps twenty 
miles in diameter, perhaps less, and from this spread 
radially till they attain a width of seventy-five or one 
hundred miles. If the oasis be associated with a double 
canal, thi3 maximum width exactly fits the space be- 
tween the twin lines. Even when no double enters 
the oasis, the size is about the same. This size attained, 
they hold it for some months. Then they proceed to 

chap, xxvii OASES; KINEMATIC 333 

fade out to their initial nucleus , and after a sufficient 
rest the process starts over againj 

With the carets something of the same sort seems to 
take place if we may consider as betokening a gen- 
eral law the fact that in 1894 the carets at the mouths 
of the Phison and Euphrates developed before their 
affiliated canals. But about them much less is yet 
known, and we must be content to say that the obser- 
vations of 1905 made at the opposite season of the 
canal's year seem to bear this out. 





A S rational science does not rest content with raw 
results, it now becomes obligatory, by mar- 
shaling the facts to suitable discussion, to seek to find 
out what they mean. Now, so soon as we scan these 
phenomena for some self-interpretation, we perceive 
one characteristic of the lines which at once appears 
to direct us to their nature and justifies itself as a sign- 
post with increasing certainty as we read on. This 
trait is the very simple yet most significant one of 
showing intrinsic change : the lines alter in visibility 
with time. This primary proclivity we do not even need 
the cartouches to establish. That the lines change is 
palpable to any one who will watch them long enough. 
Schiaparelli was struck by the fact early in his study of 
the planet, and it forces itself on the notice of any care- 
ful observer who compares his own observations with 
one another at intervals. But though the cartouches are 
not needed to a first revelation of mutability, they serve 
to certify and precise it to much further information on 
the subject. For, that these changes are not extrinsic, 
that is, are not caused by varying definition, distance, 

z 337 

338 MARS AND ITS CANALS chap, xxvm 

or illumination, they make patent even to those who 
have never seen the things themselves by disclosing 
respective differences of behavior in lines similarly 
circumstanced optically. The change is therefore 
intrinsic, and the question arises to what can such in- 
trinsic change be due. 

In searching for cause, attention is at once attracted 
by another series of transmutations that manifests 
itself upon the disk, in the orderly melting of the polar 
caps. For the existence of the two sets of metamor- 
phoses suggests the possibility of a connection between 
them. The inference is strengthened when we note 
that not only are both periodic, but that furthermore 
the period of the two is the same. Each polar cap 
runs through its gamut of change in a Martian year; 
the canals also complete their cycle of growth and decay 
in a Martian twelvemonth. The only difference be- 
tween the two is that each polar cap has but one maxi- 
mum and one minimum in the course of this time, 
while most of the canals have two of each, though the 
maxima are not alike nor the minima either) 

Not only is the period of the two series of changes the 
same, but the one follows the other. For the develop- 
ment of the canals does not begin till the melting of the 
polar cap is well under way. Now, as the polar cap 
disintegrates it gives rise, as we have seen, to a dark belt 
of blue-green which fringes its outer edge and retreats 


with it as it shrinks. This tells, directly or indirectly, 
of a product let loose. After this belt has been formed 
the canals nearest to it proceed to darken, then those a 
little farther off follow suit, and so the wave of visibility 
rolls in regular routine down the disk. Here, then, at 
the outset we have a chronic connection between the 
two phenomena, the disintegration of the cap and the 
integration of the canalso 

Of water we saw that the caps were undoubtedly 
composed, and to water, then, let loose by the melting 
of the cap, we may inferably ascribe the thaumaturgy 
in the development of the canals. But it is not neces- 
sary to suppose that this is done directly. That the 
increased visibility of the canals can be due to a bodily 
transference of water seems doubtful, if for no other 
reason than the delay in the action. Considerable 
time intervenes between the disappearance of the 
cap and the appearance of the canals, except in the 
case of such as have been covered by it. Transforma- 
tion consequent upon transference, however, would 
account for hesitancy. A quickening to vegetal 
growth would produce the counterpart of what we 
see. If, set free from the winter locking up, the water 
accumulated in the cap then percolated equatorward, 
starting vegetation in its course, this would cause 
the increased visibility of the canals and at the same 
time explain the seeming delay, by allowing for the 

340 MARS AND ITS CANALS ohaf. xxtiii 

time necessary for this vegetation to sprout. This 
is certainly the most satisfactory explanation of the 

Thus started, the vegetal quickening would pass 
down the planet's surface and give rise to what we mark 
as seasonal change). But, though in one sense of sea- 
sonal character, a little consideration will show that 
it would be quite unlike the seasonal change which we 
know on earth. 

Could we see our earth from some standpoint in 
space 1 , we should mark, with the advent of spring, a 
wave of verdure sweep over its face. If freedom from 
cloud permitted of an unimpeded view, this flush of 
waking from winter's sleep would be quite evident and 
could be seen to spread. Starting from the equator so 
soon as the sun turned north, it, too, would travel north- 
ward, and, distancing the sun, arrive by midsummer 
well into the arctic zone. Here, then, we should note, 
much as we note it on Mars, a tint of blue-green super- 
pose itself successively upon the ochre ground; but 
the mundane and the Martian vegetal awakening 
would differ in one fundamental respect; the earthly 
wave would be seen to travel from equator to pole, 
while the Arian travels from pole to equator. Though 
clearly seasonal in character, both of them, the trans- 
formations would be opposite in action. Some other 
cause, then, must be at work from what we are familiar 

chap, xxviii CONSTITUTION OF CANALS 341 

with on earth. This other cause is the presence or 
absence of moisture. 

(Two factors are necessary to the begetting of vegetal 
life, the raw material and the reacting agent. Oxygen, 
nitrogen, water, and a few salts make up the first de- 
sideratum, the sun supplies the second} Unless both 
be present, the quickening to life never comes/) Now, 
the one may be there and the other not, or the other 
there and the one not. On earth the material includ- 
ing water is, except in certain destitute localities, 
always present; the sun it is that periodically with- 
draws. Observant upon the return of the sun is there- 
fore the annual recurrence of vegetal growth. 

(On Mars, on the contrary, water is lacking} This 
we now know conclusively from other phenomena the 
disk presents which have no connection with the present 
investigation and are, therefore, unprejudiced witnesses 
to the fact. (No permanent bodies of water stud its sur- 
face. That the so-called seas are traversed by dark 
lines permanent in place is one of several proofs of this. 
The only surface water the planet knows comes from 
the melting of its polar caps. Vegetation cannot start 
until this water reaches it. Consequently, though the 
sun be ready, vegetation must wait upon the coming 
of the water, and starting from near the pole follow 
the frugal flood equatorward., 

Now, such contrariety of progression to what we 



should observe in the case of the earth could we view 
it from afar is exactly what the curves of visibility of 

Days before, fo^'i 

Days after 




/oo' /2o' /-to- /Co' /So' /Oo' /yo* /30' /oo' do' Oo' 40' JO' o' 

Phenolocv Curves -Earth. 

k - Dud Point of Vtgtation. 

(From paper in Proc. Amer. Phil. Soc, by Percival Lowell.) 

the canals exhibit. Timed primarily, not to the re- 
turn of the sun but to the advent of the water, vegetal 
quickening there follows, not the former up the lati- 
tudes but the latter down the disk. For better under- 



standing, the two curves of phenological quickening, 
the mundane and the Martian, are shown in the dia- 

S Sub-Tropu 

S Tropic 

y 7 'S. 

S. Equaton 
XEquatorial j 

S 8N. 



Days before **& 

Days after 

to 00 00 120 15 

- ., L , ,.-^^' 

. * ... -""" "* r *"""""" 

Oct So' too' 120' 140' /Co' /So' 200" 220' 240' 260' 280' joo~ J20' 


it Oead Point of Vegetation. 

(From paper in Proc. Amer. Phil. Soc, by Percival Lowell.) 

grams. The plates represent the surfaces of the two 
planets, that of the earth being shown upside down with 
south at the top so as to agree with the telescopic de- 
piction of the topography of Mars. The stars mark the 

:H4 MARS AND ITS CANALS chap, xxvm 

epoch of the dead-point of vegetation at successive 
latitudes; the time increasing toward the right. The 
curves, it will be noticed, are bowed in opposite ways. 
The bowed effect is due in part to Mercator's projec- 
tion ; in part it may represent a real decrease in speed 
with time. But what is strikingly noticeable is the 
opposite character of the advance to the right, the one 
curve running up the disk, the other down it. This 
shows that the development of vegetation proceeded in 
opposite directions over the surface. 

Thus is the opposed action upon the two planets 
accounted for, and /we are led to the conclusion that 
the canals are strips of vegetation fed by water from 
the polar caps, and that the floral seasons there as 
affecting the canals are conditioned, not as they would 
be with us, directly upon the return of the sun, but in- 
direct lv so through its direct effect upon the polar snows^ 

Once adventured on the idea of vegetation, we find 
that it explains much more than the time taken 
by the wave of canal-development down the disk. It 
accounts at once for the behavior of the canals in the 
three northern zones: the polar, arctic, and subarctic. 
The mean cartouches of these three zones dip down 
at their latter end instead of rising there, as is the case 
with the cartouches of the mean canals farther south. 
This dip denotes that the most northern canals were 
waning already by the middle of their August, though 

chap, xxviii CONSTITUTION OF CANALS 345 

the others showed no such tendency ; while the date of 
the deposition of the frost in these northern latitudes 
shows that they were started upon their course toward 
extinction before the snow itself had covered them. In 
other words, they were not obliterated but snuffed out. 
That their decline was thus preparatory to the coming 
of the first snowfall or frost-fall, sufficiently severe to 
whiten the ground so that it did not melt the next 
day, is suggestive of their constitution. It is clear 
that they were not abruptly cut off by the frost, but 
were timed by nature to such extinction. Vegetation 
would behave in just this way, since evolution would 
accommodate the career of a plant to its environment. 
The first question to present itself chronologically in 
the canals' annual history is connected with the size 
of the cap. Unfortunately for the simplicity of the 
phenomena, the cap is not an extensionless source of 
flow, but an extended surface melting from the outer 
edge in. It would seem, therefore, that water liberated 
from the outer parts should have an effect before the 
main body of it were ready to begin its general march 
down the disk. There should be, one would think, 
at least a partial action, locally, before the main action 
got under way. Now, there are certain canals that 
show cartouches increasing apparently from the time 
observations began, and the most pronounced is the 
Jaxartes, which lies of all the canals observed the farthest 

346 MARS AND ITS CANALS chap, xxvni 

north. Now, the cartouches were founded on canals 
< [uickened from the north polar cap. The farther north 
the canal, therefore, the greater the likelihood of its 
showing the phenomena. 

That we note such canals is therefore not only not 
subversive, but actually corroboratory, of the law it 
seems at first to shake. That all the canals of these 
zones do not show a like cartouche-profile is not neces- 
sary, a part of them being dependent, not upon the 
earlier, but upon the later liberated flow, and thus par- 
taking in the general law, which grows uniform lower 
down the latitudes. 

^As the action from one polar cap proceeds, not only- 
down to the equator, but across it into the planet's 
other hemisphere, it appears that much, at least, of the 
surface of Mars has two seasons of vegetal growth, the 
one quickened of the north polar cap, the other of 
the southern. How far the polar spheres of action 
overlap it is not possible at present to affirm, as the 
canals at this opposition were only visible to 35 south 
latitude. That the north polar quickening goes down 
so far is vouched for, and it is probable from other 
observed phenomena that it goes farther) 

The alternate semi-annual quickening also discloses 
itself directly in the cartouches; the previous semestral 
growth from the south polar cap actually showing in 
them before the impulse from the north began. The 

chap, xxviii CONSTITUTION OF CANALS 347 

slow falling of their curves to the minimum preceding 
their later rise is nothing less than the dying out of the 
effect started six months before from the south. The 
gentler gradient of their fall proclaims a gradual lapse, 
just as the subsequent sharper rise points to the advent 
of a fresh impulse. And this deduction seems to be 
borne out by another circumstance. There is some 
evidence of decrease in the pre-minimal gradient south- 
ward. This is telling testimony to the source whence 
the impulse came. For if it originated at the south and 
traveled northward, the southern canals would be the 
first to be affected and the first to die out, and thus 
show a longer dead season, exhibited in the cartouches 
as a more level stretch. 

Lastly, the explanation of the canals as threads of 
vegetation fays in with the one which has been found to 
meet the requirements of the blue-green areas; while 
the fact that they prove to develop as they do, re- 
versely to what would take place on earth, is exactly 
what all we have latterly learnt about the surface con- 
ditions of the planet would lead us to expect. 

From what has just been said we see that the latest 
observations at Flagstaff confirm the earlier ones, and, 
what is especially corroborative, they do so along another 
line. The former were chiefly static, the latter kine- 
matic. / In other words, the behavior of the canals in ac- 
tion bears out the testimony of their appearance at rest/) 



OTUDY of the fundamental features of Martian 
topography has disclosed, as we have seen, the 
existence of vegetation on the planet as the only ra- 
tional explanation of the dark markings there, con- 
sidered not simply on the score of their appearance 
momentarily, but judged by the changes that appear- 
ance undergoes at successive seasons of the Martian 
year. Thus we are assured that plant life exists on the 
planet. We are made aware of the fact in more ways 
than one, but most unanswerably for that trait to which 
vegetation owes its very name, its periodic quicken- 
ing to life. Thus the characteristic which has seemed 
here most distinctive of this phase of the organic, so 
that man even christened it in accordance, has proved 
equally telltale there. 

Important as a conclusion this is no less pregnant as 
a premise. For the assurance that plant life exists on 
Mars leads to a further step in extramundane acquaint- 
ance of far-reaching import. It introduces us at once 
to the probability of life there of a higher and more 
immediately appealing kind, not with the vagueness of 


chap, xxix LIFE 349 

general analogy, but with the definiteness of specific 
deduction. For the presence of a flora is itself ground 
for suspecting a fauna. 

Of a bond connecting the two we get our first hint 
the moment we look inquiringly into the world about 
us, that of our own earth. Common experience wit- 
nesses to a coexistence which grows curious and com- 
pelling as we consider it. For it is not confined to life, 
of any special order, but extends through the whole 
range of organisms of both kinds from the lowest to the 
highest. Algae and monera, orchid and mammal, occur 
side by side and with a certain considerate poverty 
or richness, as the case may be. Luxuriance in the one 
is matched by abundance in the other ; while a scanty 
flora means a poor fauna. This of which we have been 
aware in regions round about us from childhood grows 
in universality as we explore. Wherever man pene- 
trates out of his proper sphere he finds the same dual 
possession of the land or the sea, and a similar curtail- 
ing or expanding of both tenantries together. No 
mountain top so cold but that if it grow plants, it sup- 
ports insects and animals, too, after its kind ; no desert 
so arid but that creeping things find it as possible a 
habitat as life that does not stir. Even in almost 
boiling geysers animalcula and conferva? share and 
share alike. Only where extreme conditions preclude 
the one do they equally debar the other. 

350 MARS AND ITS CANALS chap, xxix 

Proceeding now from the fact to its factors we per- 
ceive reasons for this tenure in common of the land by 
the vegetal and animal kingdoms. Examination proves 
the two great divisions of the organic to be inextricably 
connected. It strikes our notice first in the relation 
of plants to animals. It is of everyday notoriety that 
animals eat plants, though it is less universally under- 
stood that in the ultimate they exist on nothing else. 
Plants furnish the food of animals; not as a matter of 
partial preference but of fundamental necessity. For 
the plant is the indispensable intermediary in the pro- 
cess of metabolism. Without plants animals would 
soon cease to exist, since they are unable to manufacture 
their own plasm out of the raw material offered by in- 
organic nature. They must make it out of the already 
prepared plasm of plants or out of other animals who 
have made it from plants. So that in the end it all 
comes back to plant production. The plant is able to 
build its plasm out of chemical substances; the animal 
cannot, except in the case of the nitro-bacteria, begin 
thus ;it the lowest rung of the alimentary ladder. 

Hut the converse of this dependence is also largely 
true. Plants are beholden to animals for processes 
that in return make their own life possible. The latter 
minister to the former with unconscious service all the 
time, and with no more arrogant independence than do 
our domesl ics generally nowadays. The inconspicuous 

chap, xxix LIFE 351 

earthworm is the fieldhand of nature's crops, who gets 
his own living by making theirs. Without this day 
and night laborer the soil for want of stirring had 
remained less capable of grass. Above ground it is the 
same story. Deprived of the ministrations of insects 
many kinds of plants would incontinently perish. By 
the solicited visits of bees and other hymenoptera 
what generically may be classed by the layman as 
flutter-bys is the plant's propagation made possible. 
Peculiarly well named, indeed, are the hymenoptera, 
seeing that they are the great matrimonial go-betweens, 
carrying pollen from one individual to another and thus 
uniting what otherwise could not meet. Spectacular 
as this widespread commerce is, it forms but portion of 
the daily drama in which animals and plants alike take 
part. From forthright bargainings of honey for help, 
we pass to less direct but no less effective alliance where 
plants are beholden to animals for life by the killing 
of their enemies or the weeding-out of their competitors, 
and from this to generic furtherance where the inter- 
dependence becomes broadcast. In the matter of 
metabolism the advantage is not all upon one side. 
In the katabolic process of that which each discards 
are the two classes of life mutually complimentary, 
the waste of the one being the want of the other, 
carbonic acid gas being given off by the animal, oxygen 
by the plant. In biologic economy it is daily more 

352 MARS AND ITS CANALS chap, xxix 

demonstrable that both are necessary constituents to 
an advancing whole, and that each pays for what it gets 
by what it gives in return. 

That they are thus ancillary as well as coexistent to- 
day leads us to confront for them a community of origin 
in the past; and further study confirms the inference. 
Both paleontology and entomology, or the science of 
the aged and the science of the young, prove such an- 
cestry to be a fact. By going back from the present 
into the past, or, what amounts to substantially the 
same thing, by descending in the scale of life to the 
lowest known forms of organism, we find proof of con- 
comitance, cogerit because congenital. At the time 
when inorganic chemical compounds first passed by 
evolution into organic ones, the change was of so general 
a character that even such tardy representatives of it 
as survive today tax erudition to tell to which of the 
two great kingdoms they belong, the vegetal or the 
animal. Simplest and most primitive of known organ- 
isms are the chromacea, unnucleated single cells as 
Haeckel has shown, and next to them in order come 
many of the bacteria, also of simple unnucleated plasm. 
So little do the majority of the bacteria differ mor- 
phologically from the chromacea, that on the score of 
structure the two are not to be catalogued apart. Both 
are as elemental as anything well can be, which only 
their diet serves to divide. Each is an organism with- 


LIFE 353 

out organs, thus belying the dictionary definition of 
both animals and plants. Etymologically they are not 
organic yet manifestly are alive, and only in their action 
are unlike. The chromacea are plasm-forming beings, 
and therefore they are plants ; the bacteria are plasm- 
eating beings, and so are animals. Even this distinc- 
tion is not always preserved. As Haeckel tells us: 
"thenitro-bacteria which dwell in the earth having the 
vegetal property of converting ammonia by oxidation 
into nitrous acid and this into nitric acid, using as their 
source of carbon the carbonic acid gas of the atmos- 
phere. They feed, like the chromacea, on simple in- 
organic compounds." Here, then, we have, close to 
the threshold of organic life, unorganized organisms, 
roughly speaking coeval and differing in a sense but 
little, either of them, from inorganic crystals; and yet 
the one is an animal, the other a plant. Progenitors 
of the two great divisions of life, they were themselves 
concomitantly evolved, either side by side or as offshoots 
both of a common stock. Now, if the ancestors of the 
two great organic kingdoms were thus simultaneously 
produced here, we are warranted in believing that they 
would similarly be produced elsewhere, given conditions 
suitably alike. In consequence, if we detect the pres- 
ence of the one, we already have an argument for infer- 
ring the other. Not to complete our syllogism would 
be to flaunt a lack of logic in nature's face. 

2 a 

354 MARS AND ITS CANALS chaf. xxix 

Rationally viewed, then, the general problem of life 
in other worlds reduces itself to a question of condi- 
tions. Since certain physical results follow inevitably 
upon certain physical premises, if we can assure our- 
selves of the proper premises we may look to nature for 
their conclusion. A priori, then, the possibility of life 
becomes one of habitat. If the environment be 
suitable life will ensue. What makes for such a 
mediary milieu is, like most cosmic processes, in its 
fundamentals of interesting simplicity; for the produc- 
tion of a proper nidus depends primarily upon the mere 
size of the body parentally concerned. If a planet be 
1 )ig enough it will inevitably bring forth life, because of 
conditions suitable to its generating; if too small it 
will remain sterile to the end of time. 

That size should be the determining factor whether 
a planet shall be fecund or barren may seem at first 
thought strange. Yet that it is so admits of no rational 
doubt. All that we see of bodies about us shows its 
truth, and what we have learnt of cosmic process enables 
us in some sort to discern why. In order for evolution, 
such as we mark it upon the earth, to be possible, the 
parent body must have been at one time at a high tem- 
perature, since only under great heat can the primal 
processes occur. Hut for this generation of caloric 
the aggregate mass of the particles, the falling together 
of which makes the planet, and their stoppage its inter- 


LIFE 355 

nal heat, must be large. The sun's rays alone are insuf- 
ficient to cause the necessary temperature; the heat 
must come from within, though it be helped from with- 
out. Even here the action is abetted by a large body. 
For a planet to entrap the sun's rays or even to preserve 
its own internal warmth, an atmosphere is needed, and 
it takes a large body to retain an atmospheric covering 
sufficiently long. Yet without it not only would there 
be no suitable state, but no medium in which organic 
or even inorganic reactions could go on. Lastly, 
water, the essential nidus for the organism's early 
stages, has its presence similarly conditioned. For this, 
like the atmosphere, would from a small body speedily 
vanish away. Thus the planet itself is the life-pro- 
ducing body, although the sun furthers the process 
when once begun. 

That the needed substances are planetarily present, 
what we know of the distribution of matter astronomi- 
cally sufficiently attests. What we find in meteorites 
shows that the catastrophe which preceded our present 
solar system's birth scattered its elemental constitu- 
ents throughout its domain, and thus when they came to 
be gathered up again into planets that these must have 
been materially the same. The manner, not the matter, 
then, is alone that about which we are concerned. 

Now, if the mass of matter gravitating together to 
form a planet be sufficient to produce the proper inor- 

856 MARS AND ITS CANALS chap, xxtx 

ganic conditions, the organic must follow as a matter of 
course . That the organic springs from the inorganic 
is not only shown by what has taken place on earth, 
but is the necessary logical deduction from its decay 
back into the inorganic again. As Nageli admirably 
observes: "The origin of the organic from the inor- 
ganic is, in the first place, not a question of experience 
and experiment, but a fact deduced from the law of 
the constancy of matter and force. If all things in the 
material world are causally related, if all phenomena 
proceed on natural principles, organisms which are 
formed of and decay into the same matter must have 
been derived originally from inorganic compounds." 

The original oneness of the two, the fact that the 
organic sprang from the inorganic, is shown by the 
cousinly closeness of the lowest organic with the high- 
est inorganic substances. The monera are suggestive 
of crystals in their uniformity of structure. Both 
are homogeneous or approximately so. Again, both 
grow by taking from what they come in contact with 
that which they find suitable and so add to their body 
by homogeneous accretion. Finally, when grown too 
large for single life, they part into similar crystals or 
split into identical cells. The difference between the 
division of the crystal and the fission of the cell is 
small in kind ; much less than that later differentiation 
in genesis into parthenogenesis and sexual reproduc- 

chap, xxix LIFE 357 

tion. Yet here we unhesitatingly trace an assured re- 
lationship. It were straining at a gnat to swallow a 
camel to doubt it in the other. 

Just as the two behave analogically alike in their 
own action, so do they observe a like attitude toward 
nature. They thus point to their common origin. 
The monera are resemblant of chemical compounds in 
their superiority to external influences. To outward 
conditions of temperature and humidity the chromacea 
are much as sticks and stones. Some species may re- 
main for long frozen in ice, Haeckel observes, and yet 
wake to activity so soon as it thaws. Others may be 
completely desiccated, and then resume their life when 
put in water after a lapse of several years. Thus both 
in their deathlike lives and in their living immortality 
the chromacea are close to inorganic things. 

From preference, however, these lowest forms of life 
affect what to us would be unbearable temperatures. 
Many of the chromacea live in hot springs at tempera- 
tures of 123 to 176 Fahrenheit, in which no other, 
that is, no higher, organism can dwell. This choice of 
habitat is in line with the other details of their evolu- 
tionary career. For it, too, is in keeping with the con- 
ditions of crystalline growth, halfway as it were on the 
road to them; the forming of crystals beginning at a 
temperature higher still. And we perceive from it 
that the passing of the inorganic into the organic is 

358 MARS AND ITS CANALS chap. taH 

brought about by a lowering of the temperature of the 
parent planet. This again, is in line with the evolu- 
tion of chemical complexity. Let the heat become less, 
and higher and higher chemical compounds, finally 
the organic ones, become possible. That evolution is 
nothing else than such a gradually increasing chemical 
synthesis is forced on one by study of the facts. Once 
started, life, as paleontology shows, develops along 
both the floral and the faunal lines side by side, taking 
on complexity with time. It begins so soon as secular 
cooling has condensed water vapor to its liquid state; 
chromacea and conferva? coming into being high up 
toward the boiling-point. Then, with lowering tem- 
perature come the seaweeds and the rhizopods, then 
the land plants and the lunged vertebrates. Hand in 
hand the fauna and flora climb to more intricate per- 
fecting, life rising as temperature lowers. 

We perceive then that, considered a priori, the possi- 
bility of life on a planet is merely a question of the 
planet's size; and then pursuantly that the character 
of that life is a matter of the planet's age. But age 
again is a question of size. For the smaller its mass the 
quicker the body cools, and with a planet, growing cold 
means growing old. Within the bounds that make life 
possible, the smaller the body the quicker it ages and 
the more advanced its denizens must be. Just how far 
the advance goes we may not assert dogmatically in 

chap, xxix LIFE 359 

a given case, since not relative age alone but absolute 
time as well is concerned in it. It may be that nature's 
processes cannot be hurried, and that for want of time 
development may in part be missed. But from general 
considerations the limit of the time needed seems well 
within most planetary careers. 

Now, the aspect of the surface of Mars shows that 
both these conditions have been fulfilled. (Mars is 
large enough to have begotten vegetation and small 
enough to be already old. All that we know of the 
physical state of the planet points to the possibility 
of both vegetal and animal life existing there, and fur- 
thermore, that this life should be of a relatively high 
order is possible. Nothing contradicts this, and the 
observations of the last ten years have rendered the 
conclusion then advanced only the more conclusive. 
Even the evidence of the past state of the planet con- 
firms that given by its present one. That with us life 
came out of the seas finds its possible parallel in the 
fact that seas seem once to have existed there, leaving 
their mark discernible to-day. Life, then, had there as 
here the wherewith to begin. That we find air and 
water in both shows that it had the means to continue 
once begun^ That it then ran a like course is further 
witnessed by what we now detect. The necessary 
premises, then, are there. More than this. /One half 
of the conclusion, vegetal life, gives evidence of itself. ) 



/~\ F the existence of animal life upon a far planet 
any evidence must, of necessity, assume a differ- 
ent guise from what its flora would present. Plant life 
should he, as on Mars we perceive it is, recognizable 
as part and parcel of the main features of the planet's 
face. In no such forthright manner could we expect 
an animal revelation. The sort of testimony which 
would render the one patent would leave the other 
obstinately hid. 

So long as animate life was in the lowest sense ani- 
mal, it would not be seen at all, though it were as wide- 
spread as the vegetal life all about it. Reason for this 
lies in their receptive character. Plants are fixtures: 
where they start they stay; while from the nature of 
their food, derived directly from the soil and from the 
air, and conditioned chiefly by warmth and moisture, 
like forms inhabit large areas and by their massed effect 
make far impression. With animals it is otherwise. 
They f(^n\ by forage, from beetle to buffalo, roaming the 
land for sustenance. Thus, both for paucity of number 
and from not a biding in one stay they must escape notice 

chap, xxx EVIDENCE 361 

at a distance such that as individuals they fail to show ; 
to say nothing of the fact that the flora usually overtop 
the fauna, and so help to hide the latter, while appear- 
ing itself distinct. Any far view of x>ur earth gives, in- 
stance of this. Seen from some panoramic- height, 
forest and moorland lie patently outspread to view, yet 
imagination is taxed to believe them tenanted at all. 
Unless man have marred the landscape not a sign 
appears of any living thing. One must be near indeed 
to note even such unusual sights as a herd of buffalo 
in the plains or those immense flights of pigeons, that 
in former years occurred like clouds darkening the air. 
From the standpoint of another planet, through any such 
direct showing animal existence would still remain un- 

Not until the creatures had reached a certain phase 
in evolution would their presence become perceptible; 
and not then directly, but by the results such presence 
brought to pass. Occupancy would be first evidenced 
by its imprint, on the land ; discernible thus initially 
not so much by the bodily as by the mind's eye. For 
not till the animal had learnt to dominate nature and 
fashion it to his needs and ends would his existence 
betray itself. By the transformation he wrought in 
the landscape would he be known. It is thus we 
should make our own far acquaintance; and by the 
disarrangement of nature first have inkling of man. 

3G2 MARS AND ITS CANALS en a.- xxx 

That it is thus we should betray ourselves, a consider- 
ation of man's history will show. While he still re- 
mained of savage simplicity, a mere child of nature, he 
might come and go unmarked by an outsider, but so 
soon as he started in to possess the earth his handicraft 
would reveal him. From the moment he bethought 
him to till the ground, he entered upon a course of 
world-subjugation of which we cannot foresee the end; 
but he has already advanced far enough to give us an 
idea of the process. It began with agriculture. De- 
forestation with its subsequent quartering of crops 
signalized his acquisition of real estate. His impress 
at first was sporadic and irregular, and in so far fol- 
lowed that of nature itself; but as it advanced it took 
on a methodism of plan. Husbandry begot thrift, 
and augmented wants demanded an increasing return 
for toil; and to this desirable end systematizatiou be- 
came a necessity. At the same time gregariousness 
grew and still further emphasized the need for economy 
of space and time. In part unconsciously, man learnt 
the laws that govern the expenditure of force and more 
and more consciously applied them. Geometry, un- 
loosed of Euclid, became a part of everyday life as in- 
sidiously as M. Jourdain found that he had been talking 
prose. Regularity rules to-day, to the lament of art. 
The railroad is straighter than the turnpike, as that is 
straighter than the trail. Communication is now too 

chap, xxx EVIDENCE 363 

urgent in its demands to know anything but law and 
take other than the shortest path to its destination. 
Tillage has undergone a like rectification. To one used 
to the patchwork quilting of the crops in older lands 
the methodical rectangles of the farms of the Great 
West are painfully exact. Yet it is more than probable 
that these material manifestations would be the first 
signs of intelligence to one considering the earth from 
far. Our towns would in all likelihood constitute the 
next ; and, lastly, the great arteries of travel that min- 
ister to their wants. Their scale, too, would render 
them the first objects to be observed. Farming as now 
practiced in Kansas or Dakota gives it a certain cos- 
mical concern ; fields for miles turning in hue with the 
rhythm of the drilled should impress an eye, if armed 
with our appliances, many millions of miles away. 

Even now we should know ourselves cosmically by 
our geometrical designs. To interplanetary under- 
standing it is this quality that would speak. Still more 
so will it tell as time goes on. As yet we are but at the 
beginning of our subjugation of the globe. We have 
hardly explored it all, still less occupied it. When we 
do so, and space shall have become enhancedly precious, 
directness of purpose with economy of result will have 
partitioned so regularly the surface of the earth as to 
impart to it an artificiality of appearance, and it becomes 
one vast coordinated expanse subservient entirely to 

364 MARS AND ITS CANALS cha- xxx 

the wants of its possessors. Centres of population 
and lines of communication, with tillage carried on in 
the most economic way ; to this it must come in the 

Nor is this outcome in any sense a circumstance acci- 
dental to the earth ; it is an inevitable phase in the evo- 
lution of organisms. As the organism develops brain 
it is able to circumvent the adversities of condition; 
and by overcoming more pronounced inhospitality of 
environment not only to survive but spread. Evi- 
dence of this thought will be stamped more and more 
visibly upon the face of its habitat. On earth, for 
all our pride of intellect, we have not yet progressed 
very far from the lowly animal state that leaves no rec- 
ords of itself. It is only in the last two centuries that 
our self-registration upon our surroundings has been 
marked. With another planet the like course must in 
all probability be pursued, and the older the life rela- 
tively to its habitat the more its signs of occupation 
should show. Intelligence on other worlds could then 
only make its presence known by such material revela- 
tion, and the sign-manuals of itself would appear more 
artificial in look as that life was high in rank. Given 
the certainty of plant-life, such markings are what one 
would look to find. Criticism which refuses to credit 
detail of the sort because too bizarre to be true writes 
itself down as unacquainted with the character of the 

chap, xxx EVIDENCE 365 

problem. For it is precisely such detail which should 
show if any evidence at all were forthcoming. 

If, now, we turn our inquiry to Mars, we shall be 
fairly startled at what its disk discloses. For we find 
ourselves confronted in the canals and oases by pre- 
cisely the appearances a priori reasoning proves should 
show were the planet inhabited. Our abstract prog- 
nostications have taken concrete form. Here in these 
rectilineal lines and roundish spots we have spread out 
our centres of effort and our lines of communication. 
For the oases are clearly ganglia to which the canals 
play the part of nerves. The strange geometricism 
which proves inexplicable on any other hypothesis now 
shows itself of the essence of the solution. The ap- 
pearance of artificiality cast up at the phenomena in 
disproof vindicates itself as the vital point in the whole 
matter. Like the cachet of an architect, it is the thing 
about the building that established the authorship. 

Though the Earth and Mars agree in being planets, 
they differ constitutionally in several important re- 
spects. Even to us the curious network that en- 
shrouds the Martian disk suggests handicraft; it 
implies it much more when considered from a Martian 



rTUIAT the canals and oases are of artificial origin 
is thus suggested by their very look ;\ when we 
come to go further and inquire into what may be their 
office 4 in the planet's economy, we find that the idea in 
addition to its general probability now acquires par- 
ticular support. For this we are indebted in part to 
study of their static aspect, but chiefly to what has 
been learnt of their kinematic action. 

I )earth of water is the key to their character. / Water 
is very scarce on the planet. We know this oy the 
absence of any bodies of it of any size upon the surface. 
So far as we can see the only available water is what 
comes from the semi-annual melting at one or the other 
cap of the snow accumulated there during the previous 
winter. Beyond this there is none except for what 
may be present in the air. Now, water is absolutely 
essential to all forms of life; no organisms can exist 
without it. 

But as a planet ages, it loses its oceans as has before 
been explained, and gradually its whole water supply. 
Life upon its surface is confronted by a growing scarcity 


of this essential to existence. For its fauna to survive 
it must utilize all it can get. To this end it would be 
obliged to put forth its chief endeavors, and the out- 
come of such work would result in a deformation of the 
disk indicative of its presence. Lines of communica- 
tion for water purposes, between the polar caps, on the 
one hand, and the centres of population, on the other, 
would be the artificial markings we should expect to 

Now, it is not a little startling that the semblance of 
just such signs of intelligent interference with nature is 
what we discern on the face of Mars, in the canals 
and oases. So dominant in its mien is the pencil-like 
directness of the canals as to be the trait that primarily 
strikes an unprejudiced observer who beholds this as- 
tounding system of lines under favorable definition 
for the first time, and its impressiveness only grows 
on him with study of the phenomena. That they 
suggested rule and compass, Schiaparelli said of them 
long ago, without committing himself as to what they 
were. In perception the great observer was, as usual, 
quite right ; and the better they are seen the more they 
justify the statement. Punctilious in their precision, 
they outdo in method all attempts of freehand drawing 
to copy them. Often has the writer tried to represent 
the regularity he saw, only to draw and redraw his lines 
in vain. Nothing short of ruling them could have 

308 MARS AND ITS CANALS chap, xxxi 

reproduced what the telescope revealed. Strange 
as their depiction may look in the drawings, the 
originals look stranger still. Indeed, that they should 
look unnatural when properly depicted is not unnatural 
if they are so in fact. For it is the geodetic precision 
which the lines exhibit that instantly stamps them 
to consciousness as artificial. The inference is so 
forthright as to be shared by those who have not 
seen them to the extent of instant denial of their 
objectivity. Drawings of them look too strange to be 
true. So scepticism imputes to the draughtsman 
their artificial fashioning, not realizing that by so doing 
it bears unconscious witness to their character. For 
in order to disprove the deduction it is driven to deny 
the fact. Now the fact can look after itself and will 
be recognized in time. For that the lines are as I have 
stated is beyond doubt. Each return of the planet 
shows them more and more geometric as sites are 
bettered and training improves. 

Suggestive of design as their initial appearance is, 
the idea of artificiality receives further sanction from 
more careful consideration, even from a static point 
of view, on at least eight counts : 

1. Their straightness ; 

2. Their individually uniform size ; 
.'*. Their extreme tenuity; 

1. The dual character of some of them ; 


5. Their position with regard to the planet's funda- 
mental features; 

6. Their relation to the oases; 

7. The character of these spots ; and, finally, 

8. The systematic networking by both canals and 
spots of the whole surface of the planet. 

Now, no natural phenomena within our knowledge 
show such regularity on such a scale upon any one of 
these eight counts, a fortiori upon all. When one con- 
siders that these lines run for thousands of miles in an 
unswerving direction, as far relatively as from London 
to Bombay, and as far actually as from Boston to San 
Francisco, the inadequacy of natural explanation 
becomes glaring. 

These several counts become more expressive of de- 
sign the farther one looks into them. Straightness 
upon a sphere means the following of an arc of a great 
circle. The lines, then, are arcs of great circles. Now, 
the great circle course is the shortest distance connect- 
ing two given points. The canals of Mars, then, prac- 
tice this economy; they connect their terminals by 
the shortest, that is, other things equal, by the quick- 
est and least wasteful path. Their preserving a uni- 
form width throughout this distance is an equally un- 
natural feature for any natural action to exhibit, but 
a perfectly natural one for an unnatural agent. For 
means of communication for whatever cause would 


370 MARS AND ITS CANALS chap, xxxi 

probably be fashioned of like countenance throughout. 
Their extreme tenuity is a third trait pointing to ar- 
tificiality; inasmuch as the narrower they are, the 
more probable is their construction by local intelli- 
gence.) Even more inexplicable, except from intent, 
is their dual character. (For them to parallel one 
another like the twin rails of a railway track, seems 
quite beyond the powers of natural causation) Enig- 
matic, indeed, from a natural standpoint, they cease 
to be so enigmatic viewed from an artificial one; and 
this the more by reason of what has lately been learnt 
of the character of their distribution. ^That they are 
found most plentifully near the equator, where the lati- 
tudinal girth is greatest, and thence diminish in num- 
bers to about latitude 60, where they disappear, 
and this not relatively to the amount of surface but 
actually, is very significant. It is quite incapable of 
natural explanation, and can only be accounted for 
on some theory of design such as lines of communica- 
tion, or canals conducting water down the latitudes for 
distribution^ So that this distribution of the doubles 
is in keeping with the law of development disclosed 
by the canals en masse. Channels and return-channels 
the two lines of the pair may be, but about this we can 
at present posit nothing. The relation may be of 
still greater complexity, and we must carefully dis- 
tinguish between surmise and deduction. 


The position of the canals, with regard to the main 
features of the disk, has a cogency of its own, an argu- 
ment from time. ^The places from which the lines start 
and to which they go are such as to imply a dependence 
of the latter upon the former chronologically. The 
lines are logically superposed upon the natural features ; 
not as if they had grown there, but as if they had been 
placed there for topographic caused Those termini 
are used which we should ourselves select for stations 
of intercommunication. For the lines not only leave 
important geodetic points, but they travel directly 
to equally salient onesA 

The connection of the canals with the oases is no less 
telltale of intent. The spots are found only at junc- 
tions, clearly the seal and sanction of such rendezvous. 
Their relation to the canals that enter them bespeaks 
method and design. Centring single lines, they are 
inclosed by doubles, a disposition such as would be 
true did they hold a pivotal position in the planet's 

The shape of the oases also suggests significance. 
Their form is round, a solid circle of shading of so deep 
a tone as to seem black, although undoubtedly in truth 
blue-green. Now, a circular area has this peculiar 
property, that it incloses for a given length of perimeter 
the maximum of space. Any other area has a longer 
inclosing boundary for the surface inclosed^ Con- 

S72 MARS AND ITS CANALS chap, xxxi 

sidering each area to be made up of onion-like envelops 
to an original core, each similar in shape to the kernel, 
we see that the property in question means that the 
average distance for points of the circular area from 
the centre is less than the same distance for those of 
any other figure. This has immediate bearing on the 
possible fashioning of such areas. (^For sufficient intelli- 
gence in the fashioners would certainly lead to a con- 
st ruction, where the greatest area could be attended to 
at the least expenditure of force. This would be where 
the distance to be traveled from the centre to all the 
desired points was on the average least ; that is, the 
area would be round) 

But last and all-embracing in its import is the system 
which the canals form, /instead of running at hap- 
hazard, the canals are interconnected in a most remark- 
able manner. They seek centres instead of avoiding 
then i. The centres are linked thus perfectly one with 
another, an arrangement which could not result from 
centres, whether of explosion or otherwise, which were 
themselves discrete. /Furthermore, the system covers 
the whole surface of the planet, dark areas and light 
ones alike, a world-wide distribution which exceeds 
the I x Minds of natural possibility) Any force which 
could act longitudinally on such a scale must be limited 
latitudinally in its action, as witness the belts of Jupiter 
or the spots upon the sun. Rotational, climatic, or 


other physical cause could not fail of zonal expression. 
Yet these lines are grandly indifferent to such compel- 
ling influences. ^Finally, the system after meshing the 
surface in its entirety runs straight into the polar caps. 

It is, then, a system whose end and aim is the tap- 
ping of the snow-cap for the water there semiannually 
let loose; then to distribute it over the planet's face.; 

Function of this very sort is evidenced by the look 
of the canals. Further study during the last eleven 
years as to their behavior leads to a like conclusion, 
while at the same time it goes much farther by reveal- 
ing the action in the case. This action proves to be 
not only in accord with the theory, but interestingly 
explanatory of the process. 

(In the first place, the canals have shown themselves, 
as they showed to Schiaparelli, to be seasonal phe- 
nomena) This negatives afresh the possibility of their 
being cracks. But furthermore, / their seasonal be- 
havior turns out to follow a law quite different from 
what we know on earth and betokens that they are in- 
debted to the melting of the polar cap for their annual 
growth, even more directly than to the sun, and that 
vegetation is the only thing that satisfactorily accounts 
for their conduct /) But again this is not all. Their 
time of quickening proceeds with singular uniformity 
down the disk, not only to, but across the equator. 
Now, this last fact has peculiar significance.} 

374 MARS AND ITS CANALS chai- xxxi 

So large are the planetary masses that no substance 
cjin resist the strains due to the cosmic forces acting 
on them to change their shape till it becomes one of 
stable equilibrium. Thus a body of planetary size, 
if unrotating, becomes a sphere except for solar tidal 
deformation; if rotating, it takes on a spheroidal forni 
exactly expressive, as far as observation goes, of the so- 
called centrifugal force at work. Mars presents such 
a figure, being flattened out to correspond to its axial 
rotation, /its surface, therefore, is in fluid equilib- 
rium, or, in other words, a particle of liquid at any 
point of its surface at the present time would stay 
where it was, devoid of inclination to move elsewhere) 

('Now, the water which quickens the verdure of the 
canals moves from the neighborhood of the pole down 
to the equator as the season advances. This it does, 
then, irrespective of gravity. No natural force propels 
it. and the inference is forthright and inevitable that it 
is artificially helped to its end. There seems to be no 
escape from this deduction. Water flows only down- 
hill, and there is no such thing as downhill on a surface 
already in fluid equilibrium)) A few canals might pre- 
sumably be so situated that their flow could, by ine- 
quality of terrane, lie equatorward, but not all. (As we 
sec on the earth, rivers flow impartially to all points of 
the compass, dependent only upon unevenness of the 
local surface conditions. Now, it is not in particular 


but by general consent that the canal system of Mars 
develops from pole to equator. 

From the respective times at which the minima take 
place, it appears that the canal-quickening occupies 
fifty-two days, as evidenced by the successive vegetal 
darkenings to descend from latitude 72 north to lati- 
tude 0, a journey of 2650 miles. This gives for the 
water a speed of fifty-one miles a day, or 2.1 miles an 
hour. The rate of progression is remarkably uniform ; 
and this abets the deduction as to assisted transference. 
The simple fact that it is carried from near the pole to 
the equator is sufficiently telltale of extrinsic aid, but 
the uniformity of the action increases its significances 

But the fact is more unnatural yet. (*The growth 
pays no regard to the equator, but proceeds across it 
as if it did not exist into the planet's other hemisphere. 
Here is something still more telling than its travel to 
this point. For even if we suppose, for the sake of ar- 
gument, that natural forces took the water down to the 
equator, their action must there be certainly reversed 
and the equator prove a dead-line to pass which were 



T I MI AT Mars is inhabited by beings of some sort 
-- or other we may consider as certain as it is 
uncertain what those beings may be) The theory of the 
existence of intelligent life on Mars may be likened to 
the atomic theory in chemistry in that in both we are 
led to the belief in units which we are alike unable to 
define. Both theories explain the facts in their re- 
spective fields and are the only theories that do, while 
as to what an atom may resemble we know as little as 
what a Martian may be like. But the behavior of 
(hemic compounds points to the existence of atoms too 
small for us to see, and in the same way the aspect and 
behavior of the Martian markings implies the action 
of agents too far away to be made out. 

But though in neither case can we tell anything of the 
bodily form of its unit, we can in both predicate a good 
deal about their workings. Apart from the gen<T;il 
fact of intelligence implied by the geometric character 
of their constructions, is the evidence as to its degree 
afforded by the cosmopolitan extent of the action* 
Girdling their globe and stretching from pole to pole, 
the Martian canal system not only embraces their 


chap, xxxii CONCLUSION 377 

whole world, but is an organized entity. Each canal 
joins another, which in turn connects with a third, and 
so on over the entire surface of the planet. This con- 
tinuity of construction posits a community of interest.) 
Now, when we consider that though not so large as the 
Earth the world of Mars is one of 4200 miles diameter 
and therefore containing something like 212,000,000 
of square miles, the unity of the process acquires 
considerable significance. The supposed vast enter- 
prises of the earth look small beside it. None of them 
but become local in comparison, gigantic as they seem 
to ^is to be. 

The first thing that is forced on us in conclusion is the 
necessarily intelligent and non-bellicose character of 
the community which could thus act as a unit through- 
out its globed War is a survival among us from savage 
times and affects now chiefly the boyish and unthinking 
element of the nation. The wisest realize that there 
are better ways for practicing heroism and other and 
more certain ends of insuring the survival of the fittest. 
It is something a people outgrow. But whether they 
consciously practice peace or not, nature in its evolu- 
tion eventually practices it for them, and after enough 
of the inhabitants of a globe have killed each other off, 
the remainder must find it more advantageous to work 
together for the common good. Whether increasing 
common sense or increasing necessity was the spur 

:i;s MARS AND ITS CANALS chap, xxxri 

that drove the Martians to this eminently sagacious 
.state we cannot say, but it is certain that reached it they 
have, and equally certain that if they had not they 
must all die. (When a planet has attained to the age of 
advancing decrepitude, and the remnant of its water 
supply resides simply in its polar caps, these can only 
be effectively tapped for the benefit of the inhabitants 
when arctic and equatorial peoples are at one. Differ- 
ence of policy on the question of the all-important 
water supply means nothing short of death. Isolated 
communities cannot there be sufficient unto themselves ; 
they must combine to solidarity or perish,. 

(From the fact, therefore, that the reticulated canal 
system is an elaborate entity embracing the whole planet 
from one pole to the other, we have not only proof of 
the world-wide sagacity of its builders, but a very sug- 
gestive side-light, to the fact that only a universal ne- 
cessity such as water could well be its underlying cause^ 
Possessed of important bearing upon the^ possibility 
of life on Mars is the rather recent appreciation that the 
habitat of both plants and animals is conditioned not 
l>y the minimum, nor by the mean temperature of the 
locality, but by the maximum heat attained in the re- 
gion. Not only is the minimum thermometric point 
no determinator of a dead-line, but even a mean tem- 
perature does not measure organic capability. The 
reason for this is that the continuance of the species 

chap, xxxii CONCLUSION 379 

seems to depend solely upon the possibility of repro- 
duction, and this in turn upon a suitable temperature 
at the critical period of the plant's or animal's career. 
Contrary to previous ideas on the subject, Merriam 
found this to be the case with the fauna of the San 
Francisco Peak region in northern Arizona. The 
region was peculiarly fitted for a test, because 
of rising a boreal island of life out of a sub- 
tropic sea of desert. It thus reproduced along its 
flanks the conditions of climates farther north, altitude 
taking the part of latitude, one succeeding another 
until at the top stood the arctic zone. Merriam 
showed that the existence of life there was dependent 
solely upon a sufficiency of warmth at the breeding sea- 
son. If that were enough the animal or plant propa- 
gated its kind, and held its foothold against adverse 
conditions during the rest of the year. This it did 
by living during its brief summer and then going into 
hibernation the balance of the time. Nature in short 
suspended its functions to a large extent for months 
together, enabling it to resurrect when the conditions 

Hibernation proves thus to be a trait acquired by the 
organism in consequence of climatic conditions. Like 
all such it can only be developed in time, since nature 
is incapable of abrupt transition. An animal suddenly 
transported from the tropic to a sub-arctic zone will 

380 MARS AND ITS CANALS chap.xmoi 

perish, because it has not yet learnt the trick of winter 
sleeping. While still characterized by seasonal in- 
somnia it is incapable of storing its energies and biding 
its time. But given time enough to acquire the art, 
its existence is determined solely by the enjoyment of 
heat enough at some season to permit of the vital pos- 
sibility of reproducing its kind. 

Diurnal shutting off of the heat affects the process 
but little, provided the fall be not below freezing at the 
hottest season. So much is shown by the fauna of our 
arctic and sub-arctic zones, but still more pertinently to 
Mars by the zones of the San Francisco Peak region, 
since the thinner air of altitude, through which a greater 
amount of heat can radiate off, is there substituted 
for the thicker one of latitudinally equal isotherms. 
Here again with the diurnal as before with the seasonal 
it is the maximum, not the mean, or, till low, even the 
minimum temperature, that tells. 

Now, with Mars the state of things is completely in 
accord with what is thus demanded for the existence of 
life. The Martian climate is one of extremes, where 
considerable heat treads on the heels of great cold. 
And the one of these two conditions is as certain as the 
other, as the condition of the planet's surface shows 
conclusively. In summer and during the day it must 
be decidedly hot, certainly well above any possible 
freezing, a thinner air blanket actually increasing the 

chap, xxxn CONCLUSION 381 

amount of heat that reaches the surface, though affect- 
ing the length of time of its retention unfavorably. 
The maximum temperature, therefore, cannot be low. 
The minimum of course is; but as we have just seen, 
it is the maximum that regulates the possibility of life. 
In spite, therefore, of a winter probably longer and 
colder than our own, organic life is not in the least de- 
barred from finding itself there. 

Indeed, the conditions appear to be such as to put a 
premium upon life of a high order. The Martian year 
being twice as long as our own, the summer is there pro- 
portionately extended. Even in the southern hemi- 
sphere, the one where the summer is the shortest, it 
lasts for 158 days, while at the same latitudes our 
own is but 90 days. This lengthening of the period of 
reproduction cannot but have an elevating effect upon 
the organism akin to the prolongation of childhood 
pointed out by John Fiske as playing so important a 
part in the evolution of the highest animals. Day and 
night, on the other hand, alternate there with approxi- 
mately the same speed as here, and except for what is 
due to a thinner air covering reproduce our own ter- 
restrial diurnal conditions, which as we saw are not 
inimical to life. 

In this respect, then, Mars proves to be by no means 
so bad a habitat. It offers another example of how 
increasing knowledge widens the domain that life may 

382 MARS AND ITS CANALS chap, xxxn 

occupy. Just as we have now found organic existence 
in abyssal depths of sea and in excessive degrees of both 
heat and cold, so do we find from exploration of our 
island mountains, which more than any other locality 
on earth facsimile the Martian surface, its possession 
there as well. / 

Another point, too, is worth consideration. Lin an 
aging world where the conditions of life have grown 
more difficult, mentality must characterize more and 
more its beings in order for them to survive, and would 
in consequence tend to be evolved. To find, therefore, 
upon Mars highly intelligent life is what the planet's 
state would lead one to expect) 

To some people it may seem that the very strange- 
ness of Martian life precludes for it an appeal to human 
interest. To me this is but a near-sighted view. The 
less the life there proves a counterpart of our earthly 
state of things, the more it fires fancy and piques in- 
quiry as to what it be. We all have felt this impulse 
in our childhood as our ancestors did before us, when 
they conjured goblins and spirits from the vasty void, 
and if our energy continue we never cease to feel its 
force through life. We but exchange, as our years in- 
crease, the romance of fiction for the more thrilling 
romance of fact. As we grow older we demand reality, 
but so this requisite be fulfilled the stranger the realiza- 
tion the better we are pleased. . Perhaps it is the more 

chap, xxxii CONCLUSION 383 

vivid imagination of youth that enables us all then to 
dispense with the hall-mark of actuality upon our cher- 
ished visions; perhaps a deeper sense of our own one- 
ness with nature as we get on makes us insist upon get- 
ting the real thing. Whatever the reason be, certain 
it is that with the years a narration, no matter how 
enthralling, takes added hold of us for being true. 
But though we crave this solid foothold for our concep- 
tions, we yield on that account no jot or tittle of our 
interest for the unexpected. 

Good reason we have for the allurement we feel 
toward what is least like us. For the wider the separa- 
tion from the familiar, the greater the parallax the new 
affords for cosmic comprehension. That which differs 
little yields little to the knowledge already possessed. 
Just as a longer base line gives us a better measure 
of the distance of the sun, so here the more diverse the 
aspects, the farther back they push the common start- 
ing-point and furnish proportionately comprehensive 
insight into the course by which each came to be what 
it is. By studying others we learn about ourselves, 
and though from the remote we learn less easily, we 
eventually learn the more. Even on the side, then, 
that touches most men, the personal, the strangeness 
of the subject should to the far-seeing prove all the 
greater magnet. 

One of the things that makes Mars of such transcen- 

384 MARS AND ITS CANALS chap, ixxd 

dent interest to man is the foresight it affords of the 
course earthly evolution is to pursue. On our own 
world we are able only to study our present and our 
past ; in Mars we are able to glimpse, in some sort, our 
future?^ Different as. the course of life on the two 
planets undoubtedly has been, the one helps, however 
imperfectly, to better understanding of the other. 

Another, more abstract but no less alluring, appeals 
to that desire innate in man to know about the cosmos 
of which he forms a part and which we call by the name 
of science. Study of Mars responds to this craving 
both directly by revelation of the secrets of another 
world and indirectly by the bearing of what we thus 
learn upon our understanding of the laws of the uni- 
verse. For the facts thus acquired broaden our con- 
ceptions in every branch of science. Some day our 
own geology, meteorology, and the rest will stand in- 
debted to study of the planet Mars for advance along 
their respective lines. Already the most alert of those 
professing them are lending ear to information from 
this source, and such cosmopolitanism can but increase 
as the years roll on. Today what we already know is 
helping to comprehension of another world; in a not 
distant future we shall be repaid with interest, and 
what that other world shall have taught us will re- 
dound to a better knowledge of our own, and of that 
cosmos of which the two form part. 

. * * tt 


i\ Hi 

. . . 

S * M f'* U * 

V * 9 




unmistakable double in 1903, 

white in, 76; 

ruddy color of, 148. 
Air (see Atmosphere), 86; 

necessity of, to life, 166, 167; 

as important to astronomical 
calculations, 7. 
Air-waves, 250, 251, 273. 
Albedo, low, 162, 167. 
Algae, 349. 

hibernation of, 317-324. 

in almost boiling geysers, 349. 
Aonium Sinus, 

two doubles suspected in, 242. 
Aquae Calidae, 208, 253, 315. 
Archaean age of the earth, 132, 

133, 138. 
Areography, 20-31; 

beginning and progress of, 109; 

three periods in, 24. 
Arizona, 16; 

in desert belt, 13; 

plateau of, 18. 

convergent double, 240. 

of canal system, 366, 368, 369, 
370, 374; 

of oases, 366, 371. 
Ascraeus Lucus, 331; 

embraced by the double Gigas, 

connection with Lucus Ismenius, 

Atmosphere, of Mars, 62, 63, 71, 

78, 79, 87-; 
shown to exist, 80, 82, 83, 84, 

163, 167; 
rare, 85, 86, 162, 167; 
effect on temperature, 80; 
constituents of, 162, 164, 166, 

Autumn, length of Martian, 

in northern hemisphere, 35, 

in southern, 35, 48. 
Axial tilt, 34, 36, 55, 155, 161 ; 
determinations of, 34, 36, 155; 
determines character of seasons, 

34, 36; 
effect of, on presentation of 

arctic and antarctic regions, 

effect of, on temperature of 

arctic and temperate regions, 



plasm-eating beings, 353. 
Barometric pressure, 63, 85. 
Beer, 23, 26, 109. 
Bilateralism, 208 ; 

inherent attribute of canals, 
Blue band, 

surrounding polar caps, 39, 40, 
42, 43, 56, 61, 63, 71, 161, 162, 
168, 338, 339. 
Blue-green areas (see Dark Re- 
gions), 32, 67, 163; 
taken for seas, 110. 
British Nautical Almanac, 35. 

development of, 304-312. 





Cambrian era of Earth, 139. 
Camera, the, 272; 
advantage of, 273; 
slower than the eye, 273; 
stars the peculiar province of, 

273, 274. 
Canals, 11, 32, 163; 
discovery of, 24, 26; 
considered straits, 27; 
regularity of, 28, 29; 
unnatural in look, 173; 
manner of introduction of, 174; 
conditions necessary to seeing 

of, 174-177, 282, 283; 
pencil-like lines, 177, 179, 367; 
definite in direction, 178; 
name, 180; 

width of, 179, 180, 182; 
length of, 183; 

visible by virtue of length, 181; 
oddities of, 183; 
number of, 184; 
systematic arrangement of , 184, 

connect with polar caps, 325, 

import of system of, 338, 372, 

373 ; 
intrinsic change in, 283, 284, 

337, 338; 
what they are not, 185-187, 373; 
zonal distribution of, 188, 189; 
departure-points, 190; 
dependent on general topog- 

raphy, 191 ; 
of later origin than main fea- 
tures. 191. 247; 
kinematic character of, 281- 

effect on, of illumination, 284; 
drawing;) of, numerous and 

consecutive. 286 J 
(.ordination of data, 2X8, 289; 
curves of visibility of (see 

Cartouches), 289, 290; 
geometricism of, 175, 206, 365, 

polar, 327. 

Canals in the dark regions, 30, 31, 
of the southern hemisphere, 

of the northern hemisphere, 

246, 247; 
detection of, 243, 245; 
deprived seas of marine charac- 
ter, 243; 
part of canal system, 244, 245, 
Caps (see Polar Caps). 
Carbon dioxide, 39, 161, 164-168. 
Carbonic era of Earth, 134, 141, 

Carets, 265-270; 

natural formations, 231, 232; 
form and position of, 266, 

reason for shape of, 268; 
associated with canals, 267, 

help in solution of riddle, 270; 
act like oases, 333. 
Cartouches of the canals, 289- 
interpretation of, 291-293, 299- 

303, 344-347; 
arranged by latitudes, 294; 
showing first frosts, 299; 
minimum points of, 297, 344; 
maximum point of, 301; 
mean canal, 297, 298. 
Cenozoic times, 144. 

obliterated by white spot, 75. 
Change, 4, 281. 

shown in polar caps, 37, 338 ; 
in blue-%reen areas, 113, 114, 
115, 120, 122-127, 163, 164; 
in canals. L68, 169, 205, 283- 

285, 314, 337, 338. 
in oases, 250-252, 330, 331, 337, 
Chromacea, 352; 

plasm-forming beings, 353; 
dose to Inorganic things, 857; 
in hot springs, 357, 358. 



Chryse, 90, 102. 
Climate, 82-89 ; 

one of extremes, 87 ; 
temperature, theoretic and ob- 
served, 87; 
non-glaciation the rule, 88. 
Clouds, 55, 71, 73, 89, 163, 165, 
283, 284; 
but few exist, 83, 165; 
none over blue-green areas, 92 ; 
of tawny dust color, 106; 
probably dust storms, 165; 
prove existence of atmosphere, 
Cold, 87, 167, 299. 
Coloe Palus, 

in connection with double 
canals, 257, 258, 263. 
Color, 74, 148 ; 

of Mare Erythraeum, 122. 

in almost boiling geysers, 349, 
Cretaceous era of the earth, 136, 

143, 151, 152. 

conditions of formation, 357. 

Dana, 131, 139, 140. 
Dark Regions, 122-125; 

thought to be seas, 110, 111; 
named in accordance, 110, 113 ; 
change in aspect cast doubt on 

marine character of , 113, 114; 
change in, considered seasonal, 

115, 120, 127, 163, 164; 
marine character lost, 30, 115- 

118, 163, 164; 
traversed by permanent lines, 

30, 31, 117, 163, 169; 
vegetation tracts, 119-127, 163, 

164, 168, 169, 170; 
below level of surrounding sur- 
face, 130, 164; 
former ocean basins, 120, 129, 

latitudinal development in, 123, 

124, 126, 127. 

Dawes, 21, 23, 249, 250, 268. 
Day, Martian, length of, 34, 160, 

Desert regions of the earth, 13, 
as observatory sites, 12, 13; 
help explain Mars, 16, 17, 156; 
color of, 149, 151; 
compared with color of Mars, 

150, 163; 
vegetation in, 150; 
position of, 153, 154; 
due to winds, 154. 
Desertism, 16, 89, 153-158. 
Deserts (see Reddish-ochre re- 
gions) . 
Deuteronilus, 259-261. 
Development of canals, 

latitudinal law of, 299, 302, 375; 
follows melting of polar caps, 

302, 338-340; 
across equator, 373. 375. 
Devonian era of the earth, 141. 
Diaphragm, the great, 265. 
Diplopia, 196. 

narrowest double, 228-230; 
embouchure of, 219-220; 
connection with Luci Ismenii, 
260, 262. 
Double Canals, 

first seen by Schiaparelli, 28, 

impression of, 193, 204; 
two classes of, 224; 
require steady definition, 194; 
phenomena of, 194, 205, 208, 

212, 213; 
physical bond between the con- 
stituents of, 226; 
connection with bays, 232; 
optical theories of, 196-203; 
not illusions, 195-203, 209; 
widths of, 205, 206, 221-224, 

229, 230, 233; 
length of, 205 ; 
seasonal change in, 205; 
constituents of, 204; 



Double Canals, original line of, 

number of, 205, 209; 
list of, 210, 211; 
gemination period of, 212, 213; 
direction of, 234-236; 
zonal distribution of, 236-239, 

distribution in longitude, 236; 
tropical phenomena, 239, 240, 

241, 242; 
compared with single canals, 240 ; 
convergent, 240; 
avoid blue-green areas, 241; 
connect with blue-green areas, 

Dust storms, 90, 165. 


tilt of axis of, 34; 

seasons on, 35; 

polar caps of, 38, 41, 44, 45, 51, 
54, 69; 

rainfall on, 79; 

viewed from space, 340; 

vegetal quickening opposite to 
that on Mars, 344. 
Eccentricity of orbit, 

effect on seasons, 46, 48, 52. 
Elevations on limb, 96, 97; 

measurement of, 98. 

white in, 75, 76. 
Eocene era of the earth, 144. 
Eopaleozoic era, 140. 
Euphrates, 221, 231, 249, 258-261, 
-'it,, 267, 316; 

continuously double, 213; 

curious relation to the Portus 
Sigaeus and Phison, 218, 219. 
Evolution, 362, 366, 367; 

planetary, 363, 364; 

advance in, dependent on en- 
vironment, 145, 146. 

polar, 54. 

relation to camera, 272-274. 

Farms in Kansas and Dakota, 363. 
Fastigium Aryn, 269; 

origin of longitudes, 23, 74. 
Fauna, 361; 

of northern Arizona, 18; 

linked with flora, 349, 350, 358. 
Flagstaff, Arizona, 16. 
Flammarion, 21, 23, 202. 
Flora, 361; 

linked with fauna, 349, 350, 358; 

fixtures, 360. 
Focal length, 

of objective in photographing 
canals, 275. 
Franz Joseph Land, 45. 

first arctic, 299, 300, 345; 

suggestive of, 87. 

Galileo, 20, 39. 
Ganges, 270; 

peculiar development of, 226- 

widest double, 228, 229. 
Gemination, 214-221. 

seasonal phenomenon, 212, 213. 

conditioned by convenience, 

shows the growing of the land, 

embracing the Ascraeus Lucus, 

embouchure of, 232. 
Gravitation, law of, 160. 

effect on atmosphere, 62 ; 

force of, on Mars, 63. 

Habitability, 159. 
Haeckel, 352, 353, 357. 

at melting of caps, 56, 64-66, 
90, 93, 165; 

recurrent, 94. 



Heat, 46, 47, 50, 146, 155. . 
Hellas, 81, 90, 91; 

in winter, 58, 59; 

ruddy color of, 148. 
Herschel, Sir W., 34, 37. 
Hibernation of canals, 313-324, 


embouchure of, 232; 

connection with Luci Ismenii, 

identical with rift, 326, 327. 
Hoarfrost, 78, 79, 81; 

at equator, 79 ; 

in southern hemisphere, 80, 92. 
Huyghens, 23, 26, 108. 

Ice sheet, 

effect of, 52. 
Illumination, oblique, 97; 

for measuring elevations, 98. 
Illusion theories of canals, 

disproved, 293. 
Image of sun, 

not reflected from dark areas, 
Insolation, 47, 79, 91. 
Intelligence on other worlds, 

method of making itself known, 
Islands south, 91, 244; 

effect of, on isothermal lines, 


original line of, 216, 217. 

polar canal, 328. 
Jupiter, 33, 372. 
Jurassic era of the earth, 136, 143, 

Juturna Fons, 

a square oasis, 263. 

Kaiser, 21, 23, 249. 
Kinetic theory of gases, 83, 146, 
147, 164. 


convergent double, 240. 

Lacus Hyperboreus, 246. 
Lampland, 197, 225, 275. 
Lick Observatory, 100. 

necessity of air and water to, 
17, 166, 167, 341; 

thin cold air no bar to, 18; 

maximum temperature deter- 
minative of, 19, 378. 380. 
Life on Earth, 349-353; 

dependent on conditions, 349- 
355, 357, 379, 380. 
Life on Mars, 169, 376; 

vegetal, 348, 359; 

probably of high order, 348, 
359, 377, 378, 381, 382; 

evidence of, 360-365. 

evidence of atmosphere, 84, 162, 
Longitudes, origin of, 23, 74. 
Lowell Observatory, 

Annals, 31, 81; 

Bulletin, 201. 
Lucus Ismenius, 19, 258; 

only double oasis, 259 ; 

association with canals, 260, 
Lucus Lunae, 330. 
Lucus Moeris, 208. 

Maedler, 21, 23, 26, 109. 

Mammal, 349. 


of Mars, 20-24, 26-29. 
Mare Acidalium, 115, 242, 246- 

white in, 80; 

darker than the Mare Ery- 
thraeum, 127. 
Mare Cimmerium, 267. 
Mare Erythraeum, 113; 

irregular lines in, 30; 

in 1903, 122-124; 

in 1905, 124-126. 



Mare Icarium, 207. 

Mare Sirenum, 92, 110, 114, 


on the moon, 109, 111; 

not seas, 112, 113; 

on Mars, 110; 

not seas, 117; 

southern hemisphere, 31. 
Matter, distribution of, 355. 
Mercator's projection, 22, 344. 
Merriam, 18, 19, 379. 
Mesozoic times of the earth, 135, 

142, 144, 151. 
Meteorology of Mars, 63, 93. 
Moisture, 86, 154. 
Monera, 349, 357; 

suggestive of crystals, 356. 
Months, Martian, 

different from our own, 36. 

not visible on Mars, 100; 

measurement of, 97-100; 

limit of height visible, 100; 

on Moon, 98, 99. 


association with Luci Ismenii, 
260, 261. 
Nageli, 356. 
Hansen, 54. 

Naval Observatory at Washing- 
ton, 16. 

shows white, 59. 
Neopaleozoic times of the Earth, 

Neptune, 33. 

Nicks in the coastline (see Carets). 
Nilokeras, double, 209; 

photographed, 225 

unlike other canals, 262 
Nitio-baetem, 350, 353. 
Nitrogen, 83, 164, 166, 341, 
.V/.r Olympica, 74, 78. 
North America, 

geologic history of, 133-137. 


detected later than canals, 30, 

three stages in appearance of, 

number of, 252 ; 
kinds of, 252-254, 263; 
shape of, 253, 371; 
position of, 254-257, 263; 
connected with canals, 256, 257, 

262, 371; 
disprove diplopic theory, 258; 
objectivity of, 263; 
in dark regions, 163, 244, 263, 

kinematic character of, 330- 

latitudinal progress of change 

in oases, 331 ; 
evolution of, 331, 332; 
intrinsic change in, 337, 338; 
at junction of canals only, 255, 

mutual corroboration of, 165, 

among mountains, 7. 
Organic Evolution, 

origin of, 356. 

of Mars, 62. 
Ovid, 25. 
Oxygen, 83, 164, 166, 167, 341. 

Paleozoic times on the Earth, 

Permian period, 142. 
Personal equation, 
eliminated, 287. 
Phenological quickening, 
on Earth, 342; 
on Mars, 343. 
Phison, 221, 231, 249, 258, 266, 
267, 316; 
continuously double, 213; 
connection with Euphrates and 
Portus Sigaeus, 218, 219. 
Phoenix Lake, 330. 



Photographs of the canals, 225, 

Photography, celestial, 271-277. 
Physiographic conditions, 

on Mars, 68, 128. 
Pickering, W. H., 330. 
Pierius, 71. 
Polar caps, 

phenomena of, 37, 41, 61; 

key to comprehension of planet, 

compared with those of earth, 
41, 46; 

composition of , 39 , 1 6 1 , 1 68 , 339 ; 

making of new, 94; 

position of, 68; 

aspect of, 56, 57; 

maxima and minima of, 38, 
41-44, 47-53, 55-57, 66-68, 

fission of, 61. 
Polar seas (see Blue band); 

fresh water, 162. 
Poles, Martian, 

determination of, 36. 
Pons Hectoris, 78. 
Portus Sigaeus, 

nicks in the coastline, 207, 266, 

embouchure to Phison and 
Euphrates, 218. 
Precipitation, 51, 79, 154, 155; 

effect on glaciation, 52. 
Presentation, a, 

defined, 287, 288. 
Probability, law of, 160. 
Projections on the terminator, 77, 
81,96, 100, 104, 165; 

color of, 102 ; 

cause of, 104-107; 

great one of 1903, 101-104; 

of 1900, 104. 
Propontis, the, 242; 

canals in, 247; 

oases in, 256. 

association with Luci Ismenii, 

Pseboas Lucus, 207, 250, 253, 
anomalous position of, 262. 

Quaternary epoch of the Earth, 

Reddish-ochre regions, 153, 155; 

deserts, 149, 156, 163; 

variations of tint in, 32, 148, 
149, 151. 
Rifts in polar cap, 61-63, 67, 162, 

permanent in place, 61, 62; 

not depressions, 62, 63, 162; 

coincide with canals, 326-328; 

explanation of, 328, 329. 

early noted, 108, 109; 

how determined, 34; 

time of, 34, 160; 

disclosed by markings, 32-34, 

Sabaeus Sinus, 23, 207, 268, 269. 
San Francisco Peaks, 18, 19, 149, 

379, 380. 
Saturn, 33. 

Scepticism, 27, 28, 204. 
Schaeberle, 30. 

Schiaparelli, 11, 15, 21, 23, 24, 26, 
27, 29, 30, 31, 34, 68, 74, 75, 
81, 114, 115, 120, 121, 173, 
177, 186, 192, 212, 217, 221, 
247, 249, 265, 282, 313, 314, 
325, 337, 367, 373. 
Seas (see Dark Regions), 
southern, 92; 
formerly on Mars and the Moon, 

internal absorption of, 147. 
Seasonal change, 
metabolic, 169; 
in canals, 168, 169, 285, 373. 

like our own, 34, 35, 166 ; 

length of, 48, 79, 161; 

of vegetal growth, 346, 347. 



Secular change, 

in canals. A] i 
Silurian era of the Earth, 134, 138, 


blotting out of, 14; 

measure of extinction of, 16. 
Sky. Martian. 89; 

clear, 165. 
Slipher, 101, 103. 
Snow, 345; 

limits of, on Earth and Mars, 
Solis Lacus, 23, 242. 
Spring, Martian, 35, 48; 

haze in, 94. 
S.S. Challenger, 

concerning south polar cap of 
earth, 45. 
S.S. Pagoda, 45. 

Subsidiary snow patches, 67, 73. 
Sun mier, Martian, 

length of, 35, 48, 381. 

relatively flat, 62, 76, 97, 

covered by canal network, 

clear-cut in good air, 258; 

in fluid equilibrium, 374; 

indicative of thin air, 162, 
Surface features, 

reality of. proved, 26, 33. 
Syrtis Major, 22; 

first marking made out, 23. 

7\ m }>< , 

white in, 77, 80. 
Temperature, 78, 147, 165, 166; 

effecl on life, 358. 

projections on, 77, 81, 96, 100- 
107, 114, 165; 

depressions on, 164. 
Terrane, 108, 265. 

shown by earth, 128, 131. 


follows terraqueousness, 129, 

131, 137, 144-146; 
earth's oceans contracting in 

size, 131 ; 
inevitably, 131, 146; 
as shown by Mars and the Moon, 

128, 130, 131; 
as shown by the geologic his- 
tory of earth, 131-137; 
as shown by paleontology, 138- 

making a better habitat, 145, 
Tertiary times of the Earth, 137, 

Thoth- Nepenthes, 

peculiar course of, 208; 
hibernation of, 315-324. 
Titan, 305. 

Triassic era, 136, 142, 152. 
Trivium Charontis, 
canals and oases in, 251, 252, 
Twilight arc, shows thin air, 85, 

Uranus, 33. 

Vegetation, 79, 119-127, 163, 166, 

169, 301; 
color of Mare Erythraeum, 122- 

proof of, 170; 
theory supported by rifts in 

polar cap, 329 ; 
most satisfactory explanation 

of phenomena of canals, 339, 

341, 344, 345, 347, 348, 373; 
two seasons of growth of, 346; 
melts snow, 328. 

dearth of, 128, 161, 163, 166, 

168, 169, 341, 366; 
loss of, inevitable, 131; 
speed of flow of, 375 ; 
from polar caps, 340, 374. 




from polar caps, 83; 

in atmosphere, 162, 168. 
Weather, 66, 89, 95. 
Wedge of Casius, 242; 

canals in, 247; 

oases in, 251, 252, 256. 

man-manufactured, 13-15. 
White spots, 32, 165; 

similar in look to polar caps, 

location and season of, 74, 76- 
79, 80, 81; 

White spots, 

permanency of, 73, 76; 

indication of temperature, 80, 
Winds, 154. 

Winter, Martian, 35, 48. 

Mars another, 4, 5, 169; 

evolution of a, 16, 128, 131, 155- 

, 158, 358. 


of Earth, 35; 
of Mars, 35, 161. 


With its applications to the determination and reduction of positions of the fixed stars 


Cloth 8vo $3.00 net 



Chapter' I. Introductory. Notes and References. 

Chapter II. Differences, Interpolation, and Development. Notes 
and References. 

Chapter III. The Method of Least Squares. Section I. Mean Values of 
Quantities. II. Determination of Probable Errors. III. Equations of Condi- 
tion. Notes and References. 


Chapter IV. Spherical Coordinates. Section I. General Theory. II. Prob- 
lems and Applications of the Theory of Spherical Coordinates. 

Chapter V. The Measure of Time and Related Problems. Section I. 
Solar and Sidereal Time. II. The General Measure of Time. III. Problems 
Involving Time. 

Chapter VI. Parallax and Related Subjects. Section I. Figure and 
Dimensions of the Earth. II. Parallax and Semi-diameter. 

Chapter VII. Aberration. 

Chapter VIII. Astronomical Refraction. Section I. The Atmosphere as a 
Refracting Medium. II. Elementary Exposition of Atmospheric Refraction. 
III. General Investigation of Astronomical Refraction. Notes and Refer- 
ences to Refraction. 

Chapter IX. Precession and Nutation. Section I. Laws of the Precessional 
Motion. II. Relative Positions of the Equator and Equinox at Widely Sepa- 
rated Epochs. III. Nutation. Notes and References to Precession 
and Nutation. 


Chapter X. Reduction of Mean Places of the Fixed Stars from one 
EPOCH TO Another. Section I. The Proper Motions of the Stars. II. Trig- 
onometric Reduction for Precession. III. Development of the Coordinates in 
the Powers of the Time. Notes and References. 

Chapter XL Reduction to Apparent Place. Section I. Reduction to Terms 
of the First Order. II. Rigorous Reduction for Close Polar Stars. III. Prac- 
tical Methods of Reduction. IV. Construction of Tables of the Apparent Places 
of Fundamental Stars. NOTES AND REFERENCES. 

Chapter XII. Method of Determining the Positions of Stars by Merid- 
ian Observations. Section I. Method of Determining Right Ascensions. 
II. The Determination of Declinations. 

Chapter XIII. Methods of Deriving the Positions and Proper Motions 
of the Stars from Published Results of Observations. Section I. 
Historical Review. II. Reduction of Catalogue Positions of Stars to a Homo- 
geneous System. III. Methods of Combining Star Catalogues. 


List of Independent Star Catalogues. 

Catalogues made at Northern Observatories. 

Catalogues made at Tropical and Southern Observatories. 


Explanation of the Tables of the Appendix. I. Constants and Formulas 
in Frequent Use. II. Tables Relating to Time and Arguments for Star Reduc- 
tions. III. Centennial Rates of the Precessional Motions. IV. Tables and 
Formulae for the Trigonometric Reduction of Mean Places of Stars. V. Reduc- 
tion of the Struve-Peters Precessions to the Adopted Values. VI. Conversion 
of Longitude and Latitude into R. A. and Dec. VII. Refractions. VIII. Co- 
efficients of Solar and- Lunar Nutation. IX. Three-place Logarithms and 
Trigonometrical Functions. 

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Q3 Lowell, Percival 

641 Mars and its canals